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THE INTERNATIONAL SCIENTIFIC SERIES.

VOLUME XV.

THE INTERNATIONAL SCIENTIFIC SERIES.

FUNGI:

PREFACE BY THE EDITOR.

As my name appears on the title-page of this volume, it isnecessary that I should exactly state what part I had in itspreparation. I had no doubt originally engaged to undertakethe work myself; but finding, from multiplicity of engagementsand my uncertain health, that I could not accomplish it satisfactorily,I thought the best course I could take was to recommendMr. Cooke to the publishers; a gentleman well known,not only in this country, but in the United States. The wholeof the work has therefore been prepared by himself, the manuscriptand proof sheets being submitted to me from time totime, in which I merely suggested such additions as seemedneedful, subjoining occasionally a few notes. As the work isintended for students, the author has had no hesitation invirepeating what has been stated in former chapters where ithas been thought to prove useful. I have no doubt thatthe same high character will justly apply to this as to Mr.Cooke’s former publications, and especially to his “Handbookof British Fungi.”

M. J. BERKELEY.

Sibbertoft,

November 23, 1874.

CONTENTS.

LIST OF ILLUSTRATIONS.

The most casual observer of Nature recognizes in almost everyinstance that comes under his notice in every-day life, withoutthe aid of logical definition, the broad distinctions between ananimal, a plant, and a stone. To him, the old definition that ananimal is possessed of life and locomotion, a plant of life withoutlocomotion, and a mineral deficient in both, seems to besufficient, until some day he travels beyond the circuit ofdiurnal routine, and encounters a sponge or a zoophyte, whichpossesses only one of his supposed attributes of animal life, butwhich he is assured is nevertheless a member of the animalkingdom. Such an encounter usually perplexes the neophyteat first, but rather than confess his generalizations to havebeen too gross, he will tenaciously contend that the spongemust be a plant, until the evidence produced is so strong thathe is compelled to desert his position, and seek refuge in thedeclaration that one kingdom runs into the other so imperceptiblythat no line of demarcation can be drawn betweenthem. Between these two extremes of broad distinction, andno distinction, lies the ground occupied by the scientific student,who, whilst admitting that logical definition fails in assigningbriefly and tersely the bounds of the three kingdoms, contends[Pg 2]that such limits exist so positively, that the universal scientificmind accepts the recognized limit without controversy or contradiction.

In like manner, if one kingdom be made the subject of inquiry,the same difficulties will arise. A flowering plant, asrepresented by a rose or a lily, will be recognized as distinctfrom a fern, a seaweed, or a fungus. Yet there are some floweringplants which, at first sight, and without examination, simulatecryptogams, as, for example, manyBalanophoræ, whichthe unscientific would at once class with fungi. It is neverthelesstrue that even the incipient botanist will accuratelyseparate the phanerogams from the cryptogams, and by meansof a little more, but still elementary knowledge, distribute thelatter amongst ferns, mosses, fungi, lichens, and algæ, withcomparatively few exceptions. It is true that between fungiand lichens there exists so close an affinity that difficulties arise,and doubts, and disputations, regarding certain small groups ora few species; but these are the exception, and not the rule.Botanists generally are agreed in recognizing the five principalgroups of Cryptogamia, as natural and distinct. In proportionas we advance from comparison of members of the three kingdoms,through that of the primary groups in one kingdom, toa comparison of tribes, alliances, and orders, we shall requirecloser observation, and more and more education of the eye tosee, and the mind to appreciate, relationships and distinctions.

We have already assumed that fungi are duly and universallyadmitted, as plants, into the vegetable kingdom. But of thisfact some have even ventured to doubt. This doubt, however,has been confined to one order of fungi, except, perhaps,amongst the most illiterate, although now the animal nature oftheMyxogastres has scarcely a serious advocate left. In thisorder the early condition of the plant is pulpy and gelatinous,and consists of a substance more allied to sarcode than cellulose.De Bary insinuated affinities withAmœba,[A] whilst Tulasne[Pg 3]affirmed that the outer coat in some of these productions containedso much carbonate of lime that strong effervescence tookplace on the application of sulphuric acid. Dr. Henry Carteris well known as an old and experienced worker amongstamœboid forms of animal life, and, when in Bombay, he devotedhimself to the examination of theMyxogastres in their earlystage, and the result of his examinations has been a firmconviction that there is no relationship whatever between theMyxogastres and the lower forms of animal life. De Bary hashimself very much modified, if not wholly abandoned, the viewsonce propounded by him on this subject. When mature, andthe dusty spores, mixed with threads, sometimes spiral, areproduced, theMyxogastres are so evidently close allies of theLycoperdons, or Puffballs, as to leave no doubt of their affinities.It is scarcely necessary to remark that the presence of zoosporesis no proof of animal nature, for not only do they occur in thewhite rust (Cystopus), and in such moulds asPeronospora,[B] butare common in algæ, the vegetable nature of which has neverbeen disputed.

There is another equally important, but more complicatedsubject to which we must allude in this connection. This isthe probability of minute fungi being developed without theintervention of germs, from certain solutions. The observationsof M. Trécul, in a paper laid before the French Academy, havethus been summarized:—1. Yeast cells may be formed in themust of beer without spores being previously sown. 2. Cells ofthe same form as those of yeast, but with different contents,arise spontaneously in simple solution of sugar, or to which alittle tartrate of ammonia has been added, and these cells arecapable of producing fermentation in certain liquids underfavourable conditions. 3. The cells thus formed producePenicilliumlike the cells of yeast. 4. On the other hand, the sporesofPenicillium are capable of being transformed into yeast.[C]The interpretation of this is, that the mouldPenicillium may be[Pg 4]produced from a sugar solution by “spontaneous generation,”and without spore or germ of any kind. The theory is, that amolecular mass which is developed in certain solutions or infusions,may, under the influence of different circumstances, produceeither animalcules or fungi. “In all these cases, no kindof animalcule or fungus is ever seen to originate from preexistingcells or larger bodies, but always from molecules.”[D]The molecules are said to form small masses, which soon melttogether to constitute a globular body, from which a processjuts out on one side. These are the so-calledTorulæ,[E] whichgive off buds which are soon transformed into jointed tubesof various diameters, terminating in rows of sporules,Penicillium,or capsules containing numerous globular seeds,Aspergillus(sic).

This is but another mode of stating the same thing as abovereferred to by M. Trécul, that certain cells, resembling yeast cells(Torula), are developed spontaneously, and that these ultimatelypass through the form of mould calledPenicillium to the morecomplexMucor (which the writer evidently has confounded withAspergillus, unless he alludes to the ascigerous form ofAspergillus,long known asEurotium). From what is now knownof the polymorphism of fungi, there would be little difficultyin believing that cells resembling yeast cells would developintoPenicillium, as they do infact in what is called the “vinegarplant,” and that the capsuliferous, or higher condition ofthis mould may be aMucor, in which the sporules are producedin capsules. The difficulty arises earlier, in the supposed spontaneousorigination of yeast cells from molecules, which resultfrom the peculiar conditions of light, temperature, &c., in whichcertain solutions are placed. It would be impossible to reviewall the arguments, or tabulate all the experiments, which havebeen employed for and against this theory. It could not bepassed over in silence, since it has been one of the stirring questionsof the day. The great problem how to exclude all germs[Pg 5]from the solutions experimented upon, and to keep them excluded,lies at the foundation of the theory. It must ever, aswe think, be matter of doubt that all germs were not excludedor destroyed, rather than one of belief that forms known to bedeveloped day by day from germs should under other conditionsoriginate spontaneously.

Fungi are veritably and unmistakably plants, of a low organization,it is true, but still plants, developed from germs,somewhat analogous, but not wholly homologous, to the seeds ofhigher orders. The process of fertilization is still obscure, butfacts are slowly and gradually accumulating, so that we mayhope at some not very distant period to comprehend what asyet are little removed from hypotheses. Admitting that fungiare independent plants, much more complex in their relationsand development than was formerly supposed, it will be expectedthat certain forms should be comparatively permanent,that is, that they should constitute good species. Here, also,efforts have been made to develop a theory that there are nolegitimate species amongst fungi, accepting the terms as hithertoapplied to flowering plants. In this, as in allied instances,too hasty generalizations have been based on a few isolatedfacts, without due comprehension of the true interpretation ofsuch facts and phenomena. Polymorphism will hereafter receivespecial illustration, but meantime it may be well to state that, becausesome forms of fungi which have been described, and whichhave borne distinct names as autonomous species, are now provedto be only stages or conditions of other species, there is no reasonfor concluding that no forms are autonomous, or that fungi whichappear and are developed in successive stages are not, in theirentirety, good species. Instead, therefore, of insinuating thatthere are no good species, modern investigation tends rather tothe establishment of good species, and the elimination of thosethat are spurious. It is chiefly amongst the microscopic speciesthat polymorphism has been determined. In the larger andfleshy fungi nothing has been discovered which can shake ourfaith in the species described half a century, or more, ago. Inthe Agarics, for instance, the forms seem to be as permanent and[Pg 6]as distinct as in the flowering plants. In fact, there is still noreason to dissent, except to a very limited extent, from whatwas written before polymorphism was accredited, that, “with afew exceptions only, it may without doubt be asserted that morecertain species do not exist in any part of the organized worldthan amongst fungi. The same species constantly recur in thesame places, and if kinds not hitherto detected present themselves,they are either such as are well known in other districts,or species which have been overlooked, and which are found onbetter experience to be widely diffused. There is nothing likechance about their characters or growth.”[F]

The parasitism of numerous minute species on living andgrowing plants has its parallel even amongst phanerogams inthe mistletoe and broom-rape and similar species. Amongstfungi a large number are thus parasitic, distorting, and in manycases ultimately destroying, their host, burrowing within thetissues, and causing rust and smut in corn and grasses, or evenmore destructive and injurious in such moulds as those of thepotato disease and its allies. A still larger number of fungiare developed from decayed or decaying vegetable matter.These are found in winter on dead leaves, twigs, branches,rotten wood, the remains of herbaceous plants, and soil largelycharged with disintegrated vegetables. As soon as a plantbegins to decay it becomes the source of a new vegetation,which hastens its destruction, and a new cycle of life commences.In these instances, whether parasitic on living plantsor developed on dead ones, the source is still vegetable. Butthis is not always the case, so that it cannot be predicated thatfungi are wholly epiphytal. Some species are always found onanimal matter, leather, horn, bone, &c., and some affect suchunpromising substances as minerals, from which it would besupposed that no nourishment could be obtained, not only hardgravel stones, fragments of rock, but also metals, such as ironand lead, of which more may be said when we come to treat ofthe habitats of fungi. Although in general terms fungi maybe described as “hysterophytal or epiphytal mycetals deriving[Pg 7]nourishment by means of a mycelium from the matrix,”[G] thereare exceptions to this rule with which the majority accord.

Of the fungi found on animal substances, none are moreextraordinary than those species which attack insects. Thewhite mould which in autumn proves so destructive to thecommon house-fly may for the present be omitted, as it isprobably a condition of one of theSaprolegniei, which someauthors include with fungi, and others with algæ. Wasps,spiders, moths, and butterflies become enveloped in a kind ofmould namedIsaria, which constitutes the conidia ofTorrubia,a genus of club-shapedSphæriæ afterwards developed. Somespecies ofIsaria andTorrubia also affect the larvæ and pupæof moths and butterflies, converting the whole interior into amass of mycelium, and fructifying in a clavate head. It hasbeen subject for discussion whether in such instances thefungus commenced its development during the life of the insect,and thus hastened its death, or whether it resulted afterdeath, and was subsequent to the commencement of decay.[H]The position in which certain large moths are found standingon leaves when infested withIsaria resembles so closely thatof the house-fly when succumbing toSporendonema Muscæ,would lead to the conclusion that certainly in some cases theinsect was attacked by the fungus whilst still living; whilst inthe case of buried caterpillars, such as the New Zealand orBritishHepialus, it is difficult to decide. Whether in life ordeath in these instances, it is clear that the silk-worm diseaseMuscardine attacks the living insect, and causes death. In thecase of theGuêpes végétantes, the wasp is said to fly about withthe fungus partially developed.

In all fungi we may recognize a vegetative and a reproductivesystem: sometimes the first only becomes developed, and thenthe fungus is imperfect, and sometimes the latter is far moreprominent than the former. There is usually an agglomerationof delicate threads, either jointed or not, which are somewhatanalogous to the roots of higher plants. These delicate threads[Pg 8]permeate the tissues of plants attacked by parasitic fungi, orthey run over dead leaves forming whitened patches, formerlybearing the name ofHimantia, but really the mycelium of somespecies ofMarasmius. If checked or disturbed, the processstops here, and only a mycelium of interwoven threads isproduced. In this condition the mycelium of one species somuch resembles that of another, that no accurate determinationcan be made. If the process goes on, this mycelium gives riseto the stem and cap of an agaricoid fungus, completing thevegetative system. This in turn gives origin to a spore-bearingsurface, and ultimately the fruit is formed, and then the fungusis complete; no fungus can be regarded as perfect or completewithout its reproductive system being developed. In some this isvery simple, in others it is as complex. In many of the moulds wehave miniature representatives of higher plants in the myceliumor roots, stem, branches, and at length capsules bearing sporidia,which correspond to seeds. It is true that leaves are absent,but these are sometimes compensated by lateral processes orabortive branchlets. A tuft of mould is in miniature a forest oftrees. Although such a definition may be deemed more poeticthan accurate, more figurative than literal, yet few could believein the marvellous beauty of a tuft of mould if they never saw itas exhibited under the microscope. In such a condition no doubtcould be entertained of its vegetable character. But there is alower phase in which these plants are sometimes encountered;they may consist only of single cells, or strings of cells, or threadsof simple structure floating in fluids. In such conditions onlythe vegetative system is probably developed, and that imperfectly,yet some have ventured to give names to isolated cells, orstrings of cells, or threads of mycelium, which really in themselvespossess none of the elements of correct classification—thevegetative system, even, being imperfect, and consequently thereproductive is absent. As already observed, no fungus is perfectwithout fruit of some kind, and the peculiarities of structureand development of fruit form one of the most important elementsin classification. To attempt, therefore, to give names to suchimperfect fragments of undeveloped plants is almost as absurd[Pg 9]as to name a flowering plant from a stray fragment of a root-fibrilaccidentally cast out of the ground—nay, even worse, foridentification would probably be easier. It is well to protestat all times against attempts to push science to the verge ofabsurdity; and such must be the verdict upon endeavours todetermine positively such incomplete organisms as floating cells,or hyaline threads which may belong to any one of fifty speciesof moulds, or after all to an alga. This leads us to remark, inpassing, that there are forms and conditions under which fungimay be found when, fructification being absent—that is, thevegetative system alone developed—they approximate so closelyto algæ that it is almost impossible to say to which group theorganisms belong.

Finally, it is a great characteristic of fungi in general thatthey are very rapid in growth, and rapid in decay. In a nighta puffball will grow prodigiously, and in the same short perioda mass of paste may be covered with mould. In a few hours agelatinous mass ofReticularia will pass into a bladder of dust,or aCoprinus will be dripping into decay. Remembering this,mycophagists will take note that a fleshy fungus which may begood eating at noon may undergo such changes in a few hoursas to be anything but good eating at night. Many instanceshave been recorded of the rapidity of growth in fungi; it mayalso be accepted as an axiom that they are, in many instances,equally as rapid in decay.

The affinity between lichens and fungi has long been recognizedto its full and legitimate extent by lichenologists andmycologists.[I] In the “Introduction to Cryptogamic Botany,” it[Pg 10]was proposed to unite them in one alliance, under the name ofMycetales, in the same manner as the late Dr. Lindley had unitedallied orders under alliances in his “Vegetable Kingdom;” but,beyond this, there was no predisposition towards the theorysince propounded, and which, like all new theories, has collecteda small but zealous circle of adherents. It will be necessarybriefly to summarize this theory and the arguments by which itis supported and opposed, inasmuch as it is intimately connectedwith our subject.

As recently as 1868, Professor Schwendener first propoundedhis views,[J] and then briefly and vaguely, that all and everyindividual lichen was but an algal, which had collected about ita parasitic fungal growth, and that those peculiar bodies which,under the name ofgonidia, were considered as special organs oflichens, were only imprisoned algæ. In language which theRev. J. M. Crombie[K] describes as “pictorial,” this author gavethe general conclusion at which he had arrived, as follows:—“Asthe result of my researches, all these growths are not simpleplants, not individuals in the usual sense of the term; theyare rather colonies, which consist of hundreds and thousandsof individuals, of which, however, only one acts as master, whilethe others, in perpetual captivity, provide nourishment for themselvesand their master. This master is a fungus of the orderAscomycetes, a parasite which is accustomed to live upon the workof others; its slaves are green algæ, which it has sought out, orindeed caught hold of, and forced into its service. It surrounds[Pg 11]them, as a spider does its prey, with a fibrous net of narrowmeshes, which is gradually converted into an impenetrablecovering. While, however, the spider sucks its prey and leavesit lying dead, the fungus incites the algæ taken in its net tomore rapid activity; nay, to more vigorous increase.” Thishypothesis, ushered upon the world with all the prestige of theProfessor’s name, was not long in meeting with adherents, andthe cardinal points insisted upon were—1st. That the genericrelationship of the coloured “gonidia” to the colourless filamentswhich compose the lichen thallus, had only been assumed,and not proved; 2nd. That the membrane of the gonidia waschemically different from the membrane of the other tissues,inasmuch as the first had a reaction corresponding to that ofalgæ, whilst the second had that of fungi; 3rd. That thedifferent forms and varieties of gonidia corresponded withparallel types of algæ; 4th. That as the germination of thespore had not been followed further than the development of ahypothallus, it might be accounted for by the absence of theessential algal on which the new organism should become parasitic;5th. That there is a striking correspondence between thedevelopment of the fruit in lichens and in some of the sporidiiferousfungi (Pyrenomycetes).

These five points have been combated incessantly by lichenologists,who would really be supposed by ordinary minds to bethe most practically acquainted with the structure and developmentof these plants, in opposition to the theorists. It is a factwhich should have some weight, that no lichenologist of reputehas as yet accepted the theory. In 1873 Dr. E. Bornet[L] cameto the aid of Schwendener, and almost exhausted the subject,but failed to convince either the practised lichenologist ormycologist. The two great points sought to be established arethese, that what we call lichens are compound organisms, notsimple, independent vegetable entities; and that this compoundorganism consists of unicellular algæ, with a fungus parasiticupon them. The coloured gonidia which are found in the[Pg 12]substance, or thallus of lichens, are the supposed algæ; and thecellular structure which surrounds, encloses, and imprisons thegonidia is the parasitic fungus, which is parasitic on somethinginfinitely smaller than itself, and which it entirely and absolutelyisolates from all external influences.

Dr. Bornet believed himself to have established that everygonidium of a lichen may be referred to a species of algæ, andthat the connection between the hypha and gonidia is of such anature as to exclude all possibility of the one organ being producedby the other. This he thinks is the only way in which itcan be accounted for that the gonidia of diverse lichens shouldbe almost identical.

Dr. Nylander, in referring to this hypothesis of an imprisonedalgal,[M] writes: “The absurdity of such an hypothesis is evidentfrom the very consideration that it cannot be the case that anorgan (gonidia) should at the same time be a parasite on thebody of which it exercises vital functions; for with equalpropriety it might be contended that the liver or the spleenconstitutes parasites of the mammiferæ. Parasite existence isautonomous, living upon a foreign body, of which natureprohibits it from being at the same time an organ. This isan elementary axiom of general physiology. But observationdirectly made teaches that the green matter originally ariseswithin the primary chlorophyll- or phycochrom-bearing cellule,and consequently is not intruded from any external quarter, norarises in any way from any parasitism of any kind. The celluleat first is observed to be empty, and then, by the aid of secretion,green matter is gradually produced in the cavity and assumes adefinite form. It can, therefore, be very easily and evidentlydemonstrated that the origin of green matter in lichens is entirelythe same as in other plants.” On another occasion, and inanother place, the same eminent lichenologist remarks,[N] as tothe supposed algoid nature of gonidia—“that such an unnaturalexistence as they would thus pass, enclosed in a prison and[Pg 13]deprived of all autonomous liberty, is not at all consonant withthe manner of existence of the other algæ, and that it has noparallel in nature, for nothing physiologically analogous occursanywhere else. Krempelhuber has argued that there are noconclusive reasons against the assumption that the lichen-gonidiamay be self-developed organs of the lichen proper rather thanalgæ, and that these gonidia can continue to vegetate separately,and so be mistaken for unicellular algæ.” In this Th. Friesseems substantially to concur. But there is one strong argument,or rather a repetition of an argument already cited, placedin a much stronger light, which is employed by Nylander in thefollowing words:—“So far are what are called algæ, accordingto the turbid hypothesis of Schwendener, from constituting truealgæ, that on the contrary it may be affirmed that they have alichenose nature, whence it follows that these pseudo-algæ arein a systematic arrangement to be referred rather to the lichens,and that the class of algæ hitherto so vaguely limited should becircumscribed by new and truer limits.”

As to another phase in this question, there are, as Krempelhuberremarks, species of lichens which in many countries donot fructify, and whose propagation can only be carried on bymeans of the soredia, and the hyphæ of such could in themselvesalone no more serve for propagation than the hyphæ from thepileus or stalk of an Agaric, while it is highly improbable thatthey could acquire this faculty by interposition of a foreignalgal. On the other hand he argues: “It is much more conformableto nature that the gonidia, as self-developed organs ofthe lichens, should, like the spores, enable the hyphæ proceedingfrom them to propagate the individual.”[O]

A case in point has been adduced[P] in which gonidia wereproduced by the hypha, and the genusEmericella,[Q] which isallied toHusseia in theTrichogastres, shows a structure in thestem exactly resemblingPalmella botryoides of Greville, and towhat occurs inSynalyssa.Emericella, with one or two other[Pg 14]genera, must, however, be considered as connectingTrichogastreswith lichens, and the question cannot be considered as satisfactorilydecided till a series of experiments has been made onthe germination of lichen spores and their relation to free algæconsidered identical with gonidia. Mr. Thwaites was the firstto point out[R] the relation of the gonidia in the different sectionsof lichens to different types of supposed algæ. The questioncannot be settled by mereà priori notions. It is, perhaps,worthy of remark that inChionyphe Carteri the threads growover the cysts exactly as the hypha of lichens is represented asgrowing over the gonidia.

Recently, Dr. Thwaites has communicated his views on onephase of this controversy,[S] which will serve to illustrate thequestion as seen from the mycological side. As is well known,this writer has had considerable experience in the study of theanatomy and physiology of all the lower cryptogamia, and anysuggestion of his on such a subject will at least commend itselfto a patient consideration.

“According to our experience,” he writes, “I think parasiticfungi invariably produce a sad effect upon the tissues they fixthemselves upon or in. These tissues become pale in colour,and in every respect sickly in appearance. But who has everseen the gonidia of lichens the worse for having the ‘hypha’growing amongst them? These gonidia are always in theplumpest state, and with the freshest, healthiest colour possible.Cannot it enter into the heads of these most patient and excellentobservers, that a cryptogamic plant may have two kindsof tissue growing side by side, without the necessity of onebeing parasitic upon the other, just as one of the higher plantsmay have half a dozen kinds of tissue making up its organization?The beautifully symmetrical growth of the same lichenshas seemed to me a sufficient argument against one portionbeing parasitic upon another, but when we see all harmony androbust health, the idea that one portion is subsisting parasiticallyupon another appears to me to be a perfect absurdity.”

It appears to us that a great deal of confusion and a largenumber of errors which creep into our modern generalizationsand hypotheses, may be traced to the acceptance of analogiesfor identities. How many cases of mistaken identity has theimprovement of microscopes revealed during the past quarterof a century. This should at least serve as a caution for thefuture.

Apart, however, from the “gonidia,” whatever they may be,is the remainder of the lichen a genuine fungus? Nylanderwrites, “The anatomical filamentose elements of lichens aredistinguished by various characters from the hyphæ of fungi.They are firmer, elastic, and at once present themselves in thetexture of lichens. On the other hand, the hyphæ of fungi arevery soft, they possess a thin wall, and are not at all gelatinous,while they are immediately dissolved by the application ofhydrate of potash, &c.”[T]

Our own experience is somewhat to the effect, that there aresome few lichens which are doubtful as to whether they arefungi or lichens, but, in by far the majority of cases, there isnot the slightest difficulty in determining, from the peculiarfirmness and elasticity of the tissues, minute peculiarities whichthe practised hand can detect rather than describe, and eventhe general character of the fruit that they differ materiallyfrom, though closely allied to fungi. We have only experienceto guide us in these matters, but that is something, and we haveno experience in fungi of anything like aCladonia, howevermuch it may resemble aTorrubia orClavaria. We havePezizæwith a subiculum in the sectionTapesia, but the veriest tyrowould not confound them with species ofParmelia. It is truethat a great number of lichens, at first sight, and casually,resemble species of theHysteriacei, but it is no less strangethan true, that lichenologists and mycologists know their ownsufficiently not to commit depredations on each other.

Contributions are daily being made to this controversy, andalready the principal arguments on both sides have appeared in[Pg 16]an English dress,[U] hence it will be unnecessary to repeat thosewhich are modifications only of the views already stated, ourown conclusions being capable of a very brief summary: thatlichens and fungi are closely related the one to the other, butthat they are not identical; that the “gonidia” of lichensare part of the lichen-organization, and consequently are notalgæ, or any introduced bodies; that there is no parasitism;and that the lichen thallus, exclusive of gonidia, is whollyunknown amongst fungi.

The Rev. J. M. Crombie has therefore our sympathies in theremark with which his summary of the gonidia controversycloses, in which he characterizes it as a “sensational romance oflichenology,” of the “unnatural union between a captive algaldamsel and a tyrant fungal master.”

Without some knowledge of the structure of fungi, it is scarcelypossible to comprehend the principles of classification, or toappreciate the curious phenomena of polymorphism. Yet thereis so great a variety in the structure of the different groups,that this subject cannot be compressed within a few paragraphs,neither do we think that this would be desired if practicable,seeing that the anatomy and physiology of plants is, in itself,sufficiently important and interesting to warrant a rather extendedand explicit survey. In order to impart as much practicalutility as possible to this chapter, it seems advisable totreat some of the most important and typical orders and subordersseparately, giving prominence to the features which arechiefly characteristic of those sections, following the order ofsystematists as much as possible, whilst endeavouring to rendereach section independent to a considerable extent, and completein itself. Some groups naturally present more noteworthyfeatures than others, and will consequently seem to receivemore than their proportional share of attention, but this seeminginequality could scarcely have been avoided, inasmuch ashitherto some groups have been more closely investigated thanothers, are more intimately associated with other questions, orare more readily and satisfactorily examined under differentaspects of their life-history.

Fig. 1.—Agaric in Process of Growth.

Agaricini.—For the structure that prevails in the order towhich the mushroom belongs, an examination of that specieswill be almost sufficient. Here we shall at once recognize[Pg 18]three distinct parts requiring elucidation, viz. the rootingslender fibres that traverse the soil, and termed themycelium,or spawn, the stem and cap or pileus, which together constitutewhat is called thehymenophore, and the plates or gillson the under surface of the cap, which bear thehymenium.The earliest condition in which the mushroom can be recognizedas a vegetable entity is in that of the “spawn” or mycelium,which is essentially an agglomeration of vegetating spores. Itsnormal form is that of branched, slender, entangled, anastomosing,hyaline threads. At certain privileged points of the mycelium,the threads seem to be aggregated, and become centresof vertical extension. At first only a small nearly globose budding,like a grain of mustard seed, is visible, but this afterwardsincreases rapidly, and other similar buddings or swellingsappear at the base.[A] These are the young hymenophore. As[Pg 19]it pushes through the soil, it gradually loses its globose form,becomes more or less elongated, and in this condition a longitudinalsection shows the position of the future gills in a pair ofopposite crescent-shaped darker-coloured spots near the apex.The dermal membrane, or outer skin, seems to be continuousover the stem and the globose head. At present, there is noexternal evidence of an expanded pileus and gills; a longitudinalsection at this stage shows that the gills are being developed,that the pileus is assuming its cap-like form, that themembrane stretching from the stem to the edge of the youngpileus is separating from the edge of the gills, and forming aveil, which, in course of time, will separate below and leave thegills exposed. When, therefore, the mushroom has arrivedalmost at maturity, the pileusexpands, and in this act theveil is torn away from themargin of the cap, and remainsfor a time like a collararound the stem. Fragmentsof the veil often remain attachedto the margin of thepileus, and the collar adherentto the stem falls back,and thenceforth is known astheannulus or ring. Wehave in this stage the fully-developedhymenophore,—thestem with its ring, supportingan expanded cap orpileus, with gills on the undersurface bearing the hymenium.[B]A longitudinal section cut through the pileus and down[Pg 20]the stem, gives the best notion of the arrangement of theparts, and their relation to the whole. By this means it will beseen that the pileus is continuous with the stem, that the substanceof the pileus descends into the gills, and that relativelythe substance of the stem is more fibrous than that of the pileus.In the common mushroom the ring is very distinct surroundingthe stem, a little above the middle, like a collar. In someAgarics the ring is very fugacious, or absent altogether. Theform of the gills, their mode of attachment to the stem, theircolour, and more especially the colour of the spores, are all veryimportant features to be attended to in the discrimination ofspecies, since they vary in different species. The wholesubstance of the Agaric is cellular. A longitudinal slice fromthe stem will exhibit under the microscope delicate tubularcells, the general direction of which is lengthwise, with lateralbranches, the whole interlacing so intimately that it is difficultto trace any individual thread very far in its course. Itwill be evident that the structure is less compact as it approachesthe centre of the stem, which in many species is hollow. Thehymenium is the spore-bearing surface, which is exposed or naked,and spread over the gills. These plates are covered on all sideswith a delicate membrane, upon which the reproductive organsare developed. If it were possible to remove this membrane inone entire piece and spread it out flat, it would cover animmense surface, as compared with the size of the pileus, for itis plaited or folded like a lady’s fan over the whole of the gill-plates,or lamellæ, of the fungus.[C] If the stem of a mushroombe cut off close to the gills, and the cap laid upon a sheet ofpaper, with the gills downwards, and left there for a few hours,when removed a number of dark radiating lines will be depositedupon the paper, each line corresponding with the intersticesbetween one pair of gills. These lines are made up of sporeswhich have fallen from the hymenium, and, if placed under themicroscope, their character will at once be made evident. Ifa fragment of the hymenium be also submitted to a similarexamination, it will be found that the whole surface is studded[Pg 21]with spores. The first peculiarity which will be observed is,that these spores are almost uniformly in groups of fourtogether. The next feature to be observed is, that each sporeis borne upon a slender stalk or sterigma, and that four of thesesterigmata proceed from the apex of a thicker projection, fromthe hymenium, called abasidium, each basidium being the supporterof four sterigmata, and each sterigma of a spore.[D] Acloser examination of the hymenium will reveal the fact thatthe basidia are accompanied by other bodies, often larger, butwithout sterigmata or spores; these have been termedcystidia,and their structure and functions havebeen the subject of much controversy.[E]Both kinds of bodies are produced onthe hymenium of most, if not all, theAgaricini.

Fig. 2.—Section of Common Mushroom.

The basidia are usually expandedupwards, so as to have more or lessof a clavate form, surmounted by fourslender points, or tubular processes,each supporting a spore; the contentsof these cells are granular, mixedapparently with oleaginous particles,which communicate through theslender tubes of the spicules withthe interior of the spores. Cordastates that, although only one spore isproduced at a time on each sporophore,when this falls away others are produced in successionfor a limited period. As the spores approach maturity, the connectionbetween their contents and the contents of the basidiadiminishes and ultimately ceases. When the basidium whichbears mature spores is still well charged with granular matter,it may be presumed that the production of a second or third[Pg 22]series of spores is quite possible. Basidia exhausted entirely oftheir contents, and which have become quite hyaline, may oftenbe observed.

Fig. 3.—a. Sterile cells.b. Basidia.c. Cystidium. FromGomphidius (de Seynes).

The cystidia are usually larger than the basidia, varying insize and form in different species. They present the appearanceof large sterile cells, attenuated upwards, sometimes into aslender neck. Corda was of opinion that these were maleorgans, and gave them the name ofpollinaires. Hoffmann hasalso described[F] both these organs under the names ofpollinariaandspermatia, but does not appear to recognize in them thesexual elements which those names would indicate; whilstde Seynes suggests that the cystidia are only organs returned tovegetative functions by a sort of hypertrophy of the basidia.[G]This view seems to be supported by the fact that, in the sectionPluteus and some others, the cystidia are surmounted by shorthorns resembling sterigmata. Hoffmann has also indicated[H]the passage of cystidia into basidia. The evidence seems to be infavour of regarding the cystidia as barren conditions of basidia.There are to be found upon the hymenium of Agarics a thirdkind of elongated cells, called by Corda[I] basilary cells, and byHoffmann “sterile cells,” which are either equal in size or smallerthan the basidia, with which also their structure agrees, exceptingin the development of spicules. These are the “proper cellsof the hymenium” of Léveillé, and are simply the terminal cellsof the gill structure—cells which, under vigorous conditions,might be developed into basidia, but which are commonlyarrested in their development. As suggested by de Seynes, thehymenium seems to be reduced to great simplicity, “one soleand self-same organ is the basis of it; according as it experiencesan arrest of development, as it grows and fructifies, or as itbecomes hypertrophied, it gives us a paraphyse, a basidium, ora cystidium—in other terms, atrophied basidium, normal basidium[Pg 23]and hypertrophied basidium; these are the three elementswhich form the hymenium.”[J]

The only reproductive organs hitherto demonstrated in Agaricsare the spores, or, as sometimes called, from their method ofproduction,basidiospores.[K] These are at first colourless, butafterwards acquire the colour peculiar to the species. In sizeand form they are, within certain limits, exceedingly variable,although form and size are tolerably constant in the samespecies. At first all are globose; as they mature, the majority areovoid or elliptic; some are fusiform, with regularly attenuatedextremities. InHygrophorus they are rather irregular, reniform,or compressed in the middle. Sometimes the external surface isrough with more or less projecting warts. Some mycologistsare of opinion that the covering of the spore is double, consistingof anexospore and anendospore, the latter being very fineand delicate. In other orders the double coating of the sporehas been demonstrated. When the spore is coloured, the externalmembrane alone appears to possesscolour, the endospore being constantlyhyaline. It may be added here,that in this order the spore is simpleand unicellular. InLactarius andRussula the trama, or inner substance,is vesicular. True latex vessels occuroccasionally inAgaricus, though notfilled with milk as inLactarius.

Fig. 4.—Polyporus giganteus (reduced).

Polyporei.—In this order the gillplates are replaced by tubes or pores,the interior of which is lined by thehymenium; indications of this structurehaving already been exhibited in some of the lower[Pg 24]Agaricini. In many cases the stem is suppressed. The substanceis fleshy inBoletus, but inPolyporus the greater numberof species are leathery or corky, and more persistent. Thebasidia, spicules, and quaternate spores agree with those ofAgaricini.[L] In fact there are no features of importance whichrelate to the hymenium in any order ofHymenomycetes (theTremellini excepted) differing from the same organ inAgaricini,unless it be the absence ofcystidia.

Fig. 5.—Hydnum repandum.

Hydnei.—Instead of pores,in this order the hymeniumis spread over the surface ofspines, prickles, or warts.[M]

Auricularini.—The hymeniumis more or less even,and in—

Clavariei the whole fungusis club-shaped, or more orless intricately branched, withthe hymenium covering theouter surface.

Fig. 6.—Calocera viscosa.

Tremellini.—In this order we have a great departure fromthe character of the substance, external appearance, and internalstructure of the other orders in this family. Here we have agelatinous substance, and the form is lobed, folded, convolute,often resembling the brain of some animal. The internal structure[Pg 25]has been specially illustrated by M. Tulasne,[N] through thecommon species,Tremella mesenterica. This latter is of afine golden yellow colour, and ratherlarge size. It is uniformly composedthroughout of a colourless mucilage,with no appreciable texture, in whichare distributed very fine, diverselybranched and anastomosing filaments.Towards the surface, the ultimatebranches of this filamentous networkgive birth, both at their summits andlaterally, to globular cells, which acquirea comparatively large size.These cells are filled with a protoplasm, to which the plantowes its orange colour. When they have attained their normaldimensions, they elongate at the summit into two, three, orfour distinct, thick, obtuse tubes, into which the protoplasmgradually passes. The developmentof these tubes is unequal and notsimultaneous, so that one will oftenattain its full dimensions, equal, perhaps,to three or four times the diameterof the generative cell, whilstthe others are only just appearing.By degrees, as each tube attains itsfull size, it is attenuated into a finepoint, the extremity of which swellsinto a spheroidal cell, which ultimatelybecomes a spore. Sometimes these tubes, or spicules,send out one or two lateral branches, each terminated by a spore.These spores (about ·006 to ·008mm. diameter) are smooth, anddeposit themselves, like a fine white dust, on the surface of theTremella and on its matrix. M. Léveillé[O] was of opinion that[Pg 26]the basidia of the Tremellini were monosporous, whilst M.Tulasne has demonstrated that they are habitually tetrasporous,as in other of the Hymenomycetes. Although agreeing in this,they differ in other features, especially in the globose form ofthe basidia, mode of production of the spicules, and, finally, thedivision of the basidia into two, three, or four cells by septawhich cut each other in their axis. This division precedes thegrowth of the spicules. It is not rare to see these cells, formedat the expense of an unilocular basidium, become partly isolatedfrom each other; in certain cases they seem to have separatedvery early, they then become larger than usual, and are groupedon the same filament so as to represent a kind of buds. Thisphenomenon usually takes place below the level of the fertilecells, at a certain depth in the mucous tissue of theTremella.

Fig. 7.—Tremella mesenterica.

Besides the reproductive system here described, Tulasne alsomade known the existence of a series of filaments which producespermatia. These filaments are often scattered and confusedwith those which produce the basidia, and not distinguishablefrom them in size or any other apparent characteristic, exceptthe manner in which their extremities are branched in order toproduce the spermatia. At other times the spermatia-bearingsurface covers exclusively certain portions of the fungus, especiallythe inferior lobes, imparting thereto a very bright orangecolour, which is communicated by the layer of spermatia,unmixed with spores. These spots retain their bright colour,while the remainder of the plant becomes pale, or covered witha white dust. The spermatia are very small, spherical, andsmooth, scarcely equalling ·002mm. They are sessile, sometimessolitary, sometimes three or four together, on theslightly swollen extremities of certain filaments of the weft ofthe fungus.[P] Tulasne found it impossible to make these corpusclesgerminate, and in all essential particulars they agreedwith the spermatia found in ascomycetous fungi.

In the genusDacrymyces, the same observer found the structure[Pg 27]to have great affinity with that ofTremella. The spores in thespecies examined were of a different form, being oblong, veryobtuse, slightly curved (·013 - ·019 × ·004 - ·006mm.), at firstunilocular, but afterwards triseptate. The basidia are cylindricalor clavate, filled with coloured granular matter; each ofthese bifurcates at the summit, and gradually elongates into twovery open branches, which are attenuated above, and ultimatelyeach is crowned by a spore. There are to be found also in thespecies of this genus globose bodies, designated “sporidioles”by M. Léveillé, which Tulasne took considerable care to trace totheir source. He thus accounts for them:—Each of the cells ofthe spore emits exteriorly one or several of these corpuscles,supported on very short and very slender pedicels, which remainafter the corpuscles are detached from them, new corpusclessucceeding the first as long as there remains any plastic matterwithin the spore. The pedicels are not all on the same plane;they are often implanted all on the same, and oftenest on theconvex side of the reproductive body. These corpuscles, thoughplaced under the most favourable conditions, never gave theleast sign of vegetation, and Tulasne concludes that they arespermatia, analogous to those produced inTremella. The sporeswhich produce spermatia are not at all apt to germinate, whilstthose which did not produce spermatia germinated freely. Henceit would appear that, although all spores seem to be perfectly identical,they have not all the same function. The same observerdetected also amongst specimens of theDacrymyces some of adarker and reddish tint, always bare of spores or spermatia onthe surface, and these presented a somewhat different structure.Where the tissue had turned red it was sterile, the constituentfilaments, ordinarily colourless, and almost empty of solid matter,were filled with a highly-coloured protoplasm; they were of lesstenuity, more irregularly thick, and instead of only rarely presentingpartitions, and remaining continuous, as in other partsof the plant, were parcelled out into an infinity of straight orcurved pieces, angular and of irregular form, especially towardsthe surface of the fungus, where they compose a sort of pulp,varying in cohesion according to the dry or moist condition of[Pg 28]the atmosphere. All parts of these reddish individuals seemedmore or less infected with this disintegration, the basidia dividedby transverse diaphragms into several cylindrical or oblongpieces, which finally become free. Transitional conditions werealso observed in mixed individuals. This sterile condition iscalled by Tulasne “gemmiparous,” and he believes that it hasere now given origin to one or more spurious species, and misledmycologists as to the real structure of perfect and fruitfulDacrymyces.

Phalloidei.—In this order the hymenium is at first enclosedwithin a sort of peridium or universal volva, maintaining asomewhat globose or egg-shape. This envelope consists of anouter and inner coat of somewhat similar texture, and an intermediategelatinous layer, often of considerable thickness. Whena section is made of the fungus, whilst still enclosed in thevolva, the hymenium is found to present numerous cavities, inwhich basidia are developed, each surmounted by spicules (fourto six) bearing oval or oblong spores.[Q] It isvery difficult to observe the structure of the hymeniumin this order, on account of its deliquescentnature. As the hymenium approaches maturity,the volva is ruptured, and the plant rapidlyenlarges. InPhallus, a long erect cellular stembears the cap, over which the hymenium isspread, and this expands enormously after escapingthe restraint of the volva. Soon after exposure,the hymenium deliquesces into a dark mucilage, colouredby the minute spores, which drips from the pileus, often diffusinga most loathsome odour for a considerable distance. InClathrus, the receptacle forms a kind of network. InAseröe,the pileus is beautifully stellate. In many the attractive formswould be considered objects of beauty, were it not for theirdeliquescence, and often fœtid odour.[R]

Fig. 8.—Basidia and spores ofPhallus.

Podaxinei.—This is a small but very curious group of fungi,in which the peridium resembles a volva, which is more or lessconfluent with the surface of the pileus. They assume hymenomycetalforms, some of them looking like Agarics, Boleti, orspecies ofHydnum, with deformed gills, pores, or spines; inMontagnites, in fact, the gill structure is very distinct. Thespores are borne in definite clusters on short pedicels in such ofthe genera as have been examined.[S]

Hypogæi.—These are subterranean puff-balls, in which sometimesa distinct peridium is present; but in most cases it consistsentirely of an external series of cells, continuous with the internalstructure, and cannot be correctly estimated as a peridium.The hymenium is sinuous and convolute, bearing basidia withsterigmata and spores in the cavities. Sometimes the cavities aretraversed by threads, as in theMyxogastres. The spores are inmany instances beautifully echinulate, sometimes globose, atothers elongated, and produced in such numbers as to lead tothe belief that their development is successive on the spicules.When fully matured, the peridia are filled with a dusty massof spores, so that it is scarcely possible in this condition to gainany notion of the structure. This is, indeed, the case withnearly allGasteromycetes. Thehypogæous fungi are curiouslyconnected withPhalloidei by the genusHysterangium.

Fig. 9.—Basidia and spores ofLycoperdon.

Trichogastres.[T]—In their early stages the species contained inthis group are not gelatinous, as in theMyxogastres, but are ratherfleshy and firm. Very little has been added to our knowledgeof structure in this group since 1839 and 1842, when one of uswrote to the following effect:—If a young plant ofLycoperdoncœlatum orL. gemmatum be cut through and examined with acommon pocket lens, it will be found to consist of a fleshy mass,[Pg 30]perforated in every direction with minute elongated, reticulated,anastomosing, labyrinthiform cavities. The resemblance of theseto the tubes ofBoleti in an early stage of growth, first led me tosuspect that there must be some very close connection betweenthem. If a very thin slice now be taken, while the mass is yetfirm, and before there is the slightest indication of a change ofcolour, the outer stratum of the walls of these cavities is foundto consist of pellucid obtuse cells, placed parallel to each otherlike the pile of velvet, exactly as in the young hymenium of anAgaric or Boletus. Occasionally one or two filaments cross fromone wall to another, and once I have seen these anastomose.At a more advanced stage of growth, four little spicules aredeveloped at the tips of the sporophores,all of which, as far as I havebeen able to observe, are fertile and ofequal height, and on each of thesespicules a globose spore is seated. Itis clear that we have here a structureidentical with that of the true Hymenomycetes,a circumstance whichaccords well with the fleshy habit andmode of growth. There is some difficultyin ascertaining the exact structureof the species just noticed, asthe fruit-bearing cells, or sporophores,are very small, and when the spicules are developed the substancebecomes so flaccid that it is difficult to cut a proper slice, evenwith the sharpest lancet. I have, however, satisfied myself asto the true structure by repeated observations. But should anydifficulty arise in verifying it in the species in question, therewill be none in doing so inLycoperdon giganteum. In thisspecies the fructifying mass consists of the same sinuous cavities,which are, however, smaller, so that the substance is more compact,and I have not seen them traversed by any filaments. Inan early stage of growth, the surface of the hymenium, that is ofthe walls of the cavities, consists of short threads composed oftwo or three articulations, which are slightly constricted at the[Pg 31]joints, from which, especially from the last, spring short branchlets,often consisting of a single cell. Sometimes two or morebranchlets spring from the same point. Occasionally the threadsare constricted without any dissepiments, the terminal articulationsare obtuse, and soon swell very much, so as greatly toexceed in diameter those on which they are seated. When arrivedat their full growth, they are somewhat obovate, and producefour spicules, which at length are surmounted each with a globosespore. When the spores are fully developed, the sporophoreswither, and if a solution of iodine be applied, which changesthe spores to a rich brown, they will be seen still adhering bytheir spicules to the faded sporophores. The spores soonbecome free, but the spicule often still adheres to them;but they are not attached to the intermingled filaments.InBovista plumbea, the spores have very long peduncles.[U] Asin theHymenomycetes, the prevailing type of reproductive organsconsisted of quaternary spores borne on spicules; so inGasteromycetes,the prevailing type, in so far as it is yet known, is verysimilar, in some cases nearly identical, consisting of a definitenumber of minute spores borne on spicules seated on basidia.In a very large number of genera, the minute structure anddevelopment of the fructification (beyond the mature spores)is almost unknown, but from analogy it may be concluded thata method prevails in a large group like theMyxogastres whichdoes not differ in essential particulars from that which is knownto exist in other groups. The difficulties in the way of studyingthe development of the spores in this are far greater than in theprevious order.

Fig. 10.—a. Threads ofTrichia.b. Portion further magnified, with spores.c. Portion of spinulose thread.

Myxogastres.—At one time that celebrated mycologist, ProfessorDe Bary, seemed disposed to exclude this group from thevegetable kingdom altogether, and relegate them to a companionshipwith amœboid forms. But in more recent works he seemsto have reconsidered, and almost, if not entirely, abandoned,that disposition. These fungi, mostly minute, are characterizedin their early stages by their gelatinous nature. The substance[Pg 32]of which they are then composed bears considerable resemblanceto sarcode, and, did they never change from this, there might besome excuse for doubting as to their vegetable nature; but as thespecies proceed towards maturity they lose their mucilaginoustexture, and become a mass of spores, intermixed with threads,surrounded by a cellular peridium. Take, for instance, the genusTrichia, and we have in the matured specimens a somewhatglobose peridium, not larger than a mustard seed, and sometimesnearly of the same colour; this ultimately ruptures andexposes a mass of minute yellow spherical spores, intermixedwith threads of the same colour.[V] These threads, when highlymagnified, exhibit in themselves a spiral arrangement, whichhas been the basis of some controversy, and in some speciesthese threads are externally spinulose. The chief controversyon these threads has been whether the spiral markings areexternal or internal, whether caused by twisting of the threador by the presence of an external or internal fibre. The spiralappearance has never been called in question, only the structurefrom whence it arises, and this, like the striæ of diatoms, isvery much an open question. Mr. Currey held that the spiral[Pg 33]appearance may be accounted for by supposing the existenceof an accurate elevation in the wall of the cell, following aspiral direction from one end of the thread to the other. Thissupposition would, he thinks, accord well with the opticalappearances, and it would account exactly for the undulationsof outline to which he alludes. He states that he had inhis possession a thread ofTrichia chrysosperma, in which thespiral appearance was so manifestly caused by an elevation ofthis nature, in which it is so clear that no internal spiral fibreexists, that he did not think there could be a doubt in the mindof any person carefully examining it with a power of 500diameters that the cause of the spiral appearance was not aspiral fibre. InArcyria, threads of a different kind are present;they mostly branch and anastomose, and are externally furnishedwith prominent warts or spines, which Mr. Currey[W] holds arealso arranged in a spiral manner around the threads. In otherMyxogastres, threads are also present without any appreciablespiral markings or spines. In the mature condition of thesefungi, they so clearly resemble, and have such close affinitieswith, the Trichogastres that one is led almost to doubt whetherit was not on hasty grounds, without due examination orconsideration, that proposals were made to remove them fromthe society of their kindred.

Fig. 11.—Arcyria incarnata, with portion of threads and spore, magnified.

Fig. 12.—Diachæa elegans.

Very little is known of the development of the spores inthis group; in the early stages the whole substance is so pulpy,and in the latter so dusty, whilst the transition from one to[Pg 34]the other is so rapid, that the relation between the spores andthreads, and their mode of attachment, has never been definitelymade out. It has been supposed that the spinulose projectionsfrom the capillitium in some species are the remainsof pedicels from which, the spores have fallen, butthere is no evidence beyond this supposition in itsfavour, whilst on the other hand, inStemonitis, forinstance, there is a profuse interlacing capillitium,and no spines have been detected. In order tostrengthen the supposition, spines should be morecommonly present. The threads, or capillitium, forma beautiful reticulated network inStemonitis,Cribraria,Diachæa,Dictydium, &c. InSpumaria,Reticularia,Lycogala, &c., they are almost obsolete.[X] Inno group is the examination of the development ofstructure more difficult, for the reasons alreadyalleged, than in the Myxogastres.

Fig. 13.—Cyathus vernicosus.

Nidulariacei.—This small group departs in someimportant particulars from the general type of structurepresent in the rest of the Gasteromycetes.[Y]The plants here included may be described under three parts,the mycelium, the peridium, and the sporangia. The myceliumis often plentiful, stout, rigid, interlacing, andcoloured, running over the surface of the soil, oramongst the vegetable débris on which the fungiestablish themselves. The peridia are seated uponthis mycelium, and in most instances are at lengthopen above, taking the form of cups, or beakers.These organs consist of three strata of tissue varyingin structure, the external being fibrous, andsometimes hairy, the interior cellular and delicate, the intermediatethick and at length tough, coriaceous, and resistant.[Pg 35]When first formed, the peridia are spherical, they then elongateand expand, the mouth being for some time closed by a veil,or diaphragm, which ultimately disappears. Within the cupslentil-shaped bodies are attached to the base and sides by elasticcords. These are the sporangia. Each of these has a complicatedstructure; externally there is a filamentous tunic,composed of interlaced fibres, sometimes called the peridiole;beneath this is the cortex, of compact homogenous structure,then follows a cellular thicker stratum, bearing, towards thecentre of the sporangia, delicate branched threads, or sporophores,on which, at their extremities,the ovate spores are generated, sometimesin pairs, but normally, it wouldseem that they are quaternary on spicules,the threads being true basidia. The wholestructure is exceedingly interesting andpeculiar, and may be studied in detail inTulasne’s memoir on this group.

Fig. 14.—Cyathus.a. Sporangium.b. Section.c. Sporophore.d. Spores.

Sphæronemei.—In this very large and,within certain limits, variable order, thereis but little of interest as regards structure,which is not better illustrated elsewhere;as, for instance, some sort of peritheciumis always present, but this canbe better studied in theSphæriacei. The spores are mostly veryminute, borne on delicate sporophores, which originate from theinner surface of the perithecia, but the majority of so-calledspecies are undoubtedly conditions of sphæriaceous fungi, eitherspermatogonia or pycnidia, and are of much more interestwhen studied in connection with the higher forms to which theybelong.[Z] Probably the number of complete and autonomousspecies are very few.

Fig. 15.—Asterosporium Hoffmanni.

Melanconiei.—Here, again, are associated together a greatnumber of what formerly were considered good species of fungi,but which are now known to be but conditions of other forms.[Pg 36]One great point of distinction between these and the precedingis the absence of any true perithecium, the spores being producedin a kind of spurious receptacle, or from a sort of stroma.The spores are, as a rule, larger and much more attractive thaninSphæronemei, and, in some instances, are either very fine, orvery curious. Under this head we may mention the multiseptatespores ofCoryneum; the tri-radiate spores ofAsterosporium;the curious crested spores ofPestalozzia; the doubly crested spores ofDilophospora; and the scarcely less singulargelatinous coated spores ofCheirospora.In all cases the fructification isabundant, and the spores frequently oozeout in tendrils, or form a black massabove the spurious receptacle from whichthey issue.[a]

Fig. 16.—Barren Cysts and Pseudospores ofLecythea.

Torulacei.—In this order there seemsat first to be a considerable resemblanceto theDematiei, except that the threads are almost obsolete, andthe plant is reduced to chains of spores, without trace of perithecium,investing cuticle, or definite stroma. Sometimes the sporesare simple, in other cases septate, and inSporochisma are at firstproduced in an investing cell. In most cases simple threadsat length become septate, and are ultimately differentiated intospores, which separate at the joints when fully mature.

Fig. 17.—Coleosporium Tussilaginis, Lev.

Fig. 18.—Melampsora salicina.

Cæomacei.—Of far greater interest are the Coniomycetousparasites on living plants. The present order includes those inwhich the spore[b] is reduced to a single cell; and here we mayobserve that, although many of them are now proved to beimperfect in themselves, and only forms or conditions of otherfungals, we shall write of them here without regard to theirduality. These originate, for the most part, within the tissuesof living plants, and are developed outwards in pustules, whichburst through the cuticle. The mycelium penetrates the intercellular[Pg 37]passages, and may sometimes be found in parts of theplants where the fungus does not develop itself. There is noproper excipulum or peridium, and the spores spring directfrom a more compacted portion of the mycelium, or from acushion-like stroma of small cells. InLecythea, the sub-globose spores are atfirst generated at the tips of shortpedicels, from which they are ultimatelyseparated; surrounding thesespores arise a series of barren cells,or cysts, which are considerably largerthe true spores, and colourless,while the spores are of some shade of yellow or orange.[c] InTrichobasis, the spores are of a similar character, sub-globose,and at first pedicellate; but there are no surrounding cysts, andthe colour is more usually brown, althoughsometimes yellow. InUredo,the spores are at first generated singly,within a mother cell; they are globose,and either yellow or brown, withoutany pedicel. InColeosporium, thereare two kinds of spores, those of apulverulent nature, globose, which aresometimes produced alone at the commencementof the season, and otherswhich originate as an elongated cell;this becomes septate, and ultimately separates at the joints.During the greater part of the year, both kinds of spores are tobe found in the same pustule. InMelampsora, the winter spores areelongated and wedge-shaped, compactedtogether closely, and are onlymatured during winter on dead leaves;the summer spores are pulverulentand globose, being, in fact, what were until recently regarded[Pg 38]as species ofLecythea. InCystopus, the spores are sub-globose,or somewhat angular, generated in a moniliform manner, andafterwards separating at the joints. The upper spore is alwaysthe oldest, continuous production of spores going on for sometime at the base of the chain. Under favourableconditions of moisture, each of these spores, orconidia, as De Bary terms them, is capable ofproducing within itself a number of zoospores;[d]these ultimately burst the vesicle, move about bythe aid of vibratile cilia, and at last settle downto germinate. Besides these, other reproductivebodies are generated upon the mycelium, withinthe tissues of the plant, in the form of globoseoogonia, or resting spores, which, when mature,also enclose great numbers of zoospores. Similaroogonia are produced amongst theMucedines inthe genusPeronospora, to which De Bary considersCystopus to be closely allied. At all events,this is a peculiarity of structure and developmentnot as yet met with in any other of theCæomacei.InUromyces is the nearest approach to thePucciniæi; in fact,it isPuccinia reduced to a single cell. The form of spore isusually more angular and irregular than inTrichobasis, and thepedicel is permanent. It may be remarked here, that of theforegoing genera, many of the species are not autonomous thathave hitherto been included amongst them. This is especiallytrue ofLecythea,Trichobasis, and, as it now appears, ofUromyces.[e]

Fig. 19.—Cystopus candidus.

Fig. 20.—Xenodochus carbonarius.

Pucciniæi.—This group differs from the foregoing chiefly inhaving septate spores. The pustules, or sori, break throughthe cuticle in a similar manner, and here also no true peridiumis present. InXenodochus, the highest development of jointsis reached, each spore being composed of an indefinite number,from ten to twenty cells. With it is associated an unicellular[Pg 39]yellow Uredine, of which it is a condition. Probably, in everyspecies of thePucciniæi, it may hereafter be proved, as it isnow suspected, that an unicellular Uredineprecedes or is associated with it, forminga condition, or secondary form of fruitof that species. Many instances of thatkind have already been traced by De Bary,[f]Tulasne, and others, and some have been alittle too rashly surmised by their followers.InPhragmidium, the pedicel is much moreelongated than inXenodochus, and the sporeis shorter, with fewer and a more definitenumber of cells for each species; Mr. Curreyis of opinion that each cell of the spore inPhragmidium has an inner globose cell,which he caused to escape by rupture of theouter cell wall as a sphæroid nucleus,[g] leading to the inferencethat each cell has its own individual power of germination andreproduction. InTriphragmium, there arethree cells for each spore, two being placedside by side, and one superimposed. In onespecies, however,Triphragmium deglubens(North American), the cells are arranged asinPhragmidium, so that this represents reallya tricellularPhragmidium, linking the presentwith the latter genus. InPucciniathe number of species is by far the mostnumerous; in this genus the spores are uniseptate,and, as in all thePucciniæi, thepeduncles are permanent. There is greatvariability in the compactness of the sporesin the sori, or pulvinules. In some species,the sori are so pulverulent that the sporesare as readily dispersed as in the Uredines,in others they are so compact as to be separated from each[Pg 40]other with great difficulty. As might be anticipated, this hasconsiderable effect on the contour of the spores, which in pulverulentspecies are shorter, broader, and more ovate than inthe compact species. If a section of one ofthe more compact sori be made, it will beseen that the majority of the spores are sideby side, nearly at the same level, their apicesforming the external surface of the sori, butit will not be unusual to observe smallerand younger spores pushing up from thehymenial cells, between the peduncles ofthe elder spores, leading to the inferencethat there is a succession of spores produced in the same pulvinule.InPodisoma, a rather anomalous genus, the septate sporesare immersed in a gelatinous stratum, and some authors haveimagined that they have an affinity with the Tremellini, butthis affinity is more apparent than real. The phenomena ofgermination, and their relations toRœstelia, if substantiated,establish their claim to a position amongst thePucciniæi.[h] Itseems to us thatGymnosporangium does not differ genericallyfromPodisoma. In a recently-characterized species,PodisomaEllisii, the spores are bi-triseptate. This is, moreover, peculiarfrom the great deficiency in the gelatinous element. In anotherNorth American species, calledGymnosporangium biseptatum,Ellis, which is distinctly gelatinous, there are similar biseptatespores, but they are considerably broader and more obtuse. Inother described species they are uniseptate.

Fig. 21.—Phragmidium bulbosum.

Fig. 22.—Pseudospores ofPuccinia.

Ustilaginei.—These fungi are now usually treated as distinctfrom theCæomacei, to which they are closely related.[i] Theyare also parasitic on growing plants, but the spores are usuallyblack or sooty, and never yellow or orange; on an average muchsmaller than in theCæomacei. InTilletia, the spores arespherical and reticulated, mixed with delicate threads, from[Pg 41]whence they spring. In the best known species,Tilletia caries,they constitute the “bunt” of wheat. The peculiarities ofgermination will be alluded to hereafter. InUstilago, theminute sooty spores are developed either on delicate threadsor in compacted cells, arising first from a sort of semi-gelatinous,grumous stroma. It is very difficult to detect any threadsassociated with the spores. The species attack the flowers andanthers of composite and polygonaceous plants, the leaves,culms, and germen of grasses, &c., and are popularly known as“smuts.” InUrocystis andThecaphora, the spores are unitedtogether into sub-globose bodies, forminga kind of compound spore. Insome species ofUrocystis, the unionwhich subsists between them is comparativelyslight. InThecaphora, onthe contrary, the complex spore, oragglomeration of spores, is compact,being at first apparently enclosed in a delicate cyst. InTuburcinia,the minute cells are compacted into a hollow sphere,having lacunæ communicating with the interior, and often exhibitingthe remains of a pedicel.

Fig. 23.—Thecaphora hyalina.

Fig. 24.—Æcidium Berberidis.

Æcidiacei.—This group differs from the foregoing threegroups prominently in the presence of a cellular peridium, whichencloses the spores; hence some mycologists have not hesitatedto propose their association with theGasteromycetes, although every otherfeature in their structure seems toindicate a close affinity with theCæomacei. The pretty cups in thegenusÆcidium are sometimes scatteredand sometimes collected in clusters,either with spermogonia in the centre or on the oppositesurface. The cups are usually white, composed of regularlyarranged bordered cells at length bursting at the apex, with themargins turned back and split into radiating teeth. The sporesare commonly of a bright orange or golden yellow, sometimeswhite or brownish, and are produced in chains, or moniliform[Pg 42]strings, slightly attached to each other,[j] and breaking off at thesummit at the same time that they continue to be produced atthe base, so that for some time there is a successive productionof spores. The spermogonia are not always readily detected, asthey are much smaller than the peridia, and sometimes precedethem. The spermatia are expelled from the lacerated andfringed apices, and are very minute and colourless. InRœsteliathe peridia are large, growing in company, and splitting longitudinallyin many cases, or by a lacerated mouth. In most instances,the spores are brownish, but in a splendid species fromNorth America (Rœstelia aurantiaca, Peck), recently characterized,they are of a bright orange. If Œrsted is correct inhis observations, which await confirmation, these species are allrelated to species ofPodisoma as a secondary form of fruit.[k]In theRœstelia of the pear-tree, as well as in that of the mountainash, the spermogonia will be found either in separate tuftson discoloured spots, or associated with theRœstelia, InPeridermiumthere is very little structural difference fromRœstelia,and the species are all found on coniferous trees. InEndophyllum,the peridia are immersed in the succulent substance ofthe matrix; whilst inGraphiola, there is a tougher and withaldouble peridium, the inner of which forms a tuft of erect threadsresembling a small brush.[l]

Fig. 25.—Helminthosporium molle.

Hyphomycetes.—The predominant feature in the structure ofthis order has already been intimated to consist in the developmentof the vegetative system under the form of simple orbranched threads, on which the fruit is generated. The commonname of mould is applied to them perhaps more generally thanto other groups, although the term is too vague, and has beentoo vaguely applied to be of much service in giving an idea ofthe characteristics of this order. Leaving the smaller groups,and confining ourselves to theDematiei and theMucedines, we[Pg 43]shall obtain some notion of the prevalent structure. In theformer the threads are more or less carbonized, in the latternearly colourless. One of the largest genera inDematiei isHelminthosporium. It appears on decaying herbaceous plants,and on old wood, forming effused black velvety patches. Themycelium, of coloured jointed threads, overlays and penetrates thematrix; from this arise erect, rigid, and usually jointed threads,of a dark brown, nearly black colourat the base, but paler towards theapex. In most cases these threadshave an externally cortical layer,which imparts rigidity; usually fromthe apex, but sometimes laterally, thespores are produced. Although sometimescolourless, these are most commonlyof some shade of brown, moreor less elongated, and divided transverselyby few or many septa. InHelminthosporium Smithii, the sporesmuch exceed the dimensions of thethreads;[m] in other species they aresmaller. InDendryphium, the threadsand spores are very similar, exceptthat the threads are branched at theirapex, and the spores are often producedone at the end of another in ashort chain.[n] InSeptosporium again,the threads and spores are similar, butthe spores are pedicellate, and attachedat or near the base; whilst inAcrothecium, with similar threads and spores, the latter areclustered together at the apex of the threads. InTriposporium,the threads are similar, but the spores are tri-radiate; and inHelicoma, the spores are twisted spirally. Thus, we might pass[Pg 44]through all the genera to illustrate this chief feature of coloured,septate, rather rigid, and mostly erect threads, bearing at somepoint spores, which in most instancesare elongated, coloured,and septate.

Fig. 26.—Acrothecium simplex.

Fig. 27.—Peronospora Arenariæ.

Mucedines.—Here, on the otherhand, the threads, if coloured atall, are still delicate, more flexuous,with much thinner walls, and neverinvested with an external corticallayer. One of the most importantand highly developed genera isPeronospora, the members of whichare parasitic upon and destructiveof living vegetables. It is to this genus that the mould of thetoo famous potato disease belongs. Professor De Bary has donemore than any other mycologist in the investigation and elucidationof this genus; and his monographis a masterpiece in its way.[o]He was, however, preceded by Mr.Berkeley, and more especially by Dr.Montagne, by many years in elucidationof the structure of the flocciand conidia in a number of species.[p]In this genus, there is a delicatemycelium, which penetrates the intercellularpassages of living plants,giving rise to erect branchedthreads, which bear at the tips oftheir ultimate ramuli, sub-globose,ovate, or elliptic spores, or, as DeBary terms them—conidia. Deeply seated on the mycelium,within the substance of the foster plant, other reproductivebodies, called oogonia, originate. These are spherical, more or[Pg 45]less warted and brownish, the contents of which become differentiatedinto vivacious zoospores, capable, when expelled, ofmoving in water by the aid of vibratile cilia. A similar structurehas already been indicated inCystopus, otherwise it is rarein fungi, if theSaprolegniei be excluded. InBotrytis and inPolyactis, the flocci and spores are similar, but the branches ofthe threads are shorter and more compact, and the septa aremore common and numerous; the oogonia also are absent. DeBary has selectedPolyactis cinerea, as it occurs on dead vineleaves, to illustrate his views of the dualismwhich he believes himself to havediscovered in this species. “It spreadsits mycelium in the tissue which is becomingbrown,” he writes, “and this showsat first essentially the same constructionand growth as that of the myceliumfilaments ofAspergillus.” On the myceliumsoon appear, besides those whichare spread over the tissue of the leaves,strong, thick, mostly fasciculate branches,which stand close to one another, breakingforth from the leaf and rising up perpendicularly,the conidia-bearers. Theygrow about 1mm. long, divide themselves,by successively rising partitions,into some prominent cylindrical linkedcells, and then their growth is ended,and the upper cell produces near itspoint three to six branches almost standingrectangularly. Of these the underones are the longest, and they again shoot forth from undertheir ends one or more still shorter little branches. Thenearer they are to the top, the shorter are the branches, andless divided; the upper ones are quite branchless, and theirlength scarcely exceeds the breadth of the principal stem. Thusa system of branches appears, upon which, on a small scale, abunch of grapes is represented. All the twigs soon end their[Pg 46]growth; they all separate their inner space from the principalstem, by means of a cross partition placed close to it. All theends, and also that of the principal stem, swell about the sametime something like a bladder, and on the upper free half ofeach swelling appear again, simultaneously, several fine protuberances,close together, which quickly grow to little ovalbladders filled with protoplasm, and resting on their bearerswith a sub-sessile, pedicellate, narrow basis, and which at lengthseparate themselves through a partition as inAspergillus. Thedetached cells are the conidia of our fungus; only one is formedon each stalk. When the formation is completed in the wholeof the panicle, the little branches which compose it are deprivedof their protoplasm in favour of the conidia; it is thesame with the under end of the principal stem, the limits ofwhich are marked by a cross partition. The delicate wall ofthese parts shrinks up until it is unrecognizable; all the conidiaof the panicle approach one another to form an irregular grape-likebunch, which rests loosely on the bearer, and from whichit easily falls away as dust. If they be brought into water theyfall off immediately; only the empty, shrivelled, delicate skinsare to be found on the branch which bore them, and the placeson which they are fixed to the principal stem clearly appear asround circumscribed hilums, generally rather arched towardsthe exterior. The development of the main stem is not endedhere. It remains solid and filled with protoplasm as far as theportion which forms the end through its conidia. Its end,which is to be found among these pieces, becomes pointed afterthe ripening of the first panicle, pushes the end of the shrivelledmember on one side, and grows to the same length as theheight of one or two panicles, and then remains still, to form asecond panicle similar to the first. This is later equally perfoliatedas the first, then a third follows, and thus a largenumber of panicles are produced after and over one another onthe same stem. In perfect specimens, every perfoliated paniclehangs loosely to its original place on the surface of the stem,until by shaking or the access of water to it, it falls immediatelyinto the single conidia, or the remains of branches, and the[Pg 47]already-mentioned oval hilums are left behind. Naturally, thestem becomes longer by every perfoliation; in luxuriant specimensthe length can reach that of some lines. Its partition isalready, by the ripening of the first panicle from the beginningof its foundation, strong and brown; it is only colourless at theend which is extending, and in all new formations. During allthese changes the filament remains either unbranched, exceptas regards the transient panicles, or it sends out here and there,at the perfoliated spots, especially from the lower ones, oneor two strong branches, standing opposite one another andresembling the principal stem.

Fig. 28.—Polyactis cinerea.a. Apex of hypha.

The mycelium, which grows so exuberantly in the leaf, oftenbrings forth many other productions, which are calledsclerotia,and are, according to their nature, a thick bulbous tissue ofmycelium filaments. Their formation begins with the profuseramification of the mycelium threads in some place or other;generally, but not always, in the veins of the leaf; the intertwiningtwigs form an uninterrupted cavity, in which is oftenenclosed the shrivelling tissue of the leaf. The whole bodyswells to a greater thickness than that of the leaf, and protrudeson the surface like a thickened spot. Its form varies fromcircular to fusiform; its size is also very unequal, rangingbetween a few lines and about half a millimetre in its largestdiameter. At first it is colourless, but afterwards its outerlayers of cells become round, of a brown or black colour, and itis surrounded by a black rind, consisting of round cells, whichseparate it from the neighbouring tissue. The tissue within therind remains colourless; it is an entangled uninterrupted tissueof fungus filaments, which gradually obtain very solid, hard,cartilaginous coats. The sclerotium, which ripens as the rindbecomes black, loosens itself easily from the place of its formation,and remains preserved after the latter is decayed.

Fig. 29.—Peziza Fuckeliana.a. Natural size.b. Section enlarged.c. Ascus and sporidia.

The sclerotia are, here as in many other fungi, biennialorgans, designed to begin a new vegetation after a state ofapparent quietude, and to send forth special fruit-bearers. Theymay in this respect be compared to the bulbs and perennialroots of under shrubs. The usual time for the development of[Pg 48]the sclerotia is late in the autumn, after the fall of the vineleaves. As long as the frost does not set in, new ones continuallyspring up, and each one attains to ripeness in a few days.If frost appears, it can lie dry a whole year, without losingits power of development. This latter commences when thesclerotium is brought into contact with damp ground duringthe usual temperature of our warmer seasons. If this occursoon, at the latest some weeks after it is ripe, new vegetationgrows very quickly, generally after a few days; in several partsthe colourless filaments of the inner tissue begin to send outclusters of strong branches, which, breaking through the blackrind, stretch themselves up perpendicularly towards the surface,separate from one another, and then takeall the characteristics of the conidia-bearers.Many such clusters can be produced on onesclerotium, so that soon the greater part ofthe surface is covered by filamentous conidia-bearerswith their panicles. The colourlesstissue of the sclerotium disappears in thesame degree as the conidia-bearers grow,and at last the black rind remains behindempty and shrivelled. If we bring, aftermany months, for the first time, the ripesclerotium, in damp ground, in summer orautumn, after it has ripened, the furtherdevelopment takes place more slowly, andin an essentially different form. It is truethat from the inner tissue numerous filamentousbranches shoot forth at the cost of this growingfascicle, and break through the black rind, but its filamentsremain strongly bound, in an almost parallel situation, to acylindrical cord, which for a time lengthens itself and spreadsout its free end to a flat plate-like disc. This is always formedof strongly united threads, ramifications of the cylindrical cord.On the free upper surface of the disc, the filaments shoot forthinnumerable branches, which, growing to the same height, thickand parallel with one another, cover the before-named disc.[Pg 49]Some remain narrow and cylindrical, are very numerous, andproduce fine hairs (paraphyses); others, also very numerous, takethe form of club-like ampulla cells, and each one forms in itsinterior eight free swimming oval spores. Those ampulla cellsare sporidiiferous asci. After the spores have become ripe, thefree point of the utricle bursts, and the spores are scattered to agreat distance by a mechanism which we will not here furtherdescribe. New ampullas push themselves between those whichare ripening and withering; a disc can, under favourable circumstances,always form new asci for weeks at a time. The numberof the already described utricle-bearers is different, accordingto the size of the sclerotium; smaller specimens usuallyproduce only one, larger two to four. The size is regulatedby that of the sclerotia, and ranges, in full-grown specimens,between one and more millimetres for the length of the stalk,and a half to three (seldom more) millimetres for the breadth ofthe disc.[q] For some time the conidia form, belonging to theMucedines, has been known asBotrytis cinerea (orPolyactiscinerea). The compact mycelium, or sclerotium, as an imperfectfungus, bore the name ofSclerotium echinatum, whilst tothe perfect and cup-like form has been given the name ofPezizaFuckeliana. We have reproduced De Bary’s life-history of thismould here, as an illustration of structure in theMucedines, buthereafter we shall have to write of similar transformations whentreating of polymorphism.

Fig. 30.—Penicillium chartarum, Cooke.

The form of the threads, and the form and disposition of thespores, vary according to the genera of which this order is composed.InOidium the mostly simple threads break up intojoints. Many of the former species are now recognized as conditionsofErysiphe. InAspergillus, the threads are simple anderect, with a globose head, around which are clustered chains ofsimple spores. InPenicillium, the lower portion of the threads issimple, but they are shortly branched at the apex, the branchesbeing terminated by necklaces of minute spores. InDactylium,[Pg 50]the threads are branched, but the spores are collected in clustersusually, and are moreover septate. In other genera similardistinctions prevail. These two groups of black moulds andwhite moulds are the noblest, and containthe largest number of genera and speciesamongst theHyphomycetes. There is, however,the small group ofIsariacei, in whichthe threads are compacted, and a semblanceof such hymenomycetal forms asClavariaandPterula is the result, but it is doubtfulif this group contains many autonomousspecies. In another small group, theStilbacei,there is a composite character in thehead, or receptacle,[r] and in the stem whenthe latter is present. Many of these, again,asTubercularia,Volutella,Fusarium, &c.,contain doubtful species. InSepedoniei andTrichodermacei, the threads are reduced to aminimum, and the spores are such a distinctiveelement that through these groups theHyphomycetesare linked with theConiomycetes. These groups, however, are notof sufficient size or importance to demand from us, in a work ofthis character, anything more than the passing allusion whichwe have given to them.

We come now to consider the structure in the Sporidiifera, inwhich the fructifying corpuscles or germs, whether called sporesor sporidia, are generated within certain privileged cysts, usuallyin definite numbers. In systematic works, these are includedunder two orders, thePhysomycetes and theAscomycetes. Theformer of these consists of cyst-bearing moulds, and from theirnearest affinity to the foregoing will occupy the first place.

Fig. 31.—Mucor mucedo, with three sporangia.a. Portion of frill with sporangiola.

Physomycetes include, especially amongst theMucorini, manymost interesting and instructive species for study, which evenvery lately have occupied the attention of continental mycologists.Most of these phenomena are associated more or lesswith reproduction, and as such will have to be adverted to again,[Pg 51]but there are points in the structure which can best be alludedto here. Again taking Professor de Bary’s researches as ourguide,[s] we will illustrate this by the commonMucor mucedo:If we bring quite fresh horse-dung into a damp confinedatmosphere, for example, under a bell-glass, there appears on itssurface, after a few days, an immense white mildew. Uprightstrong filaments of the breadth of a hair raise themselves overthe surface, each of them soon shows at its point a round littlehead, which gradually becomes black, and a closer examinationshows us that in all principal points it perfectly agrees withthe sporangia of other species.Each of these white filamentsis a sporangia-bearer. Theyspring from a mycelium whichis spread in the dung, andappear singly upon it. Certainpeculiarities in the formof the sporangium, and thelittle long cylindrical spores,which, when examined separately,are quite flat and colourless,are characteristic ofthe species. If the latter besown in a suitable medium,for example, in a solution ofsugar, they swell, and shootforth germinating utricles, which quickly grow to mycelia, whichbear sporangia. This is easily produced on the most variousorganic bodies, andMucor mucedo is therefore found spontaneouslyon every substratum which is capable of nourishingmildew, but on the above-named the most perfect and exuberantspecimens are generally to be found. The sporangia-bearersare at first always branchless and without partitions. Afterthe sporangium is ripe, cross partitions in irregular order andnumber often appear in the inner space, and on the upper[Pg 52]surface branches of different number and size, each of whichforms a sporangium at its point. The sporangia which areformed later are often very similar, but sometimes very different,to those which first appeared, because their partition is verythick and does not fall to pieces when it is ripe, but irregularlybreaks off, or remains entire, enclosing the spores, and atlast falls to the ground, when the fungus withers. The crosspartition which separates the sporangia from its bearers is inthose which are first formed (which are always relatively thickersporangia) very strongly convex, while those which follow laterare often smaller, and in little weak specimens much less arched,and sometimes quite straight. After a few days, similar filamentsgenerally show themselves on the dung between the sporangia-bearers,which appear to the naked eye to be provided with delicatewhite frills. Where such an one is to be found, two to fourrectangular expanding little branches spring up to the sameheight round the filament. Each of these, after a short andsimple process, branch out into a furcated form; the furcationsbeing made in such a manner that the ends of the branch at lastso stand together that their surface forms a ball. Finally, eachof the ends of a branch swells to a little round sporangium,which is limited by a partition (called sporangiolum, to distinguishit from the larger ones), in which some, generally four,spores are formed in the manner already known. When thesporangiola are alone, they have such a peculiar appearance, withtheir richly-branched bearers, that they can be taken for somethingquite different to the organs of theMucor mucedo, andwere formerly not considered to belong to it. That they reallybelong to theMucor is shown by the principal filament which itbears, not always, but very often, ending with a large sporangium,which is characteristic of theMucor mucedo; it is stillmore evident if we sow the spores of the sporangiolum, for, asit germinates, a mycelium is developed, which, near a simplebearer, can form large sporangia, and those form sporangiola,the first always considerably preponderating in number, andvery often exclusively. If we examine a large number of specimens,we find every possible middle form between the simple[Pg 53]or less branched sporangia-bearers and the typical sporangiolafrills; and we arrive at last at the conclusion simply to place thelatter among the varieties of form which the sporangia-bearerof theMucor mucedo shows, like every other typical organicform within certain limits. On the other hand, propagationorgans, differing from those of the sporangia and their products,belong toMucor mucedo, which may be termed conidia. Onthe dung (they are rare on any other substance) these appear atthe same time, or generally somewhat later, than the sporangia-bearers,and are not unlike those to the naked eye. In a moreaccurate examination, they appear different; a thicker, partition-lessfilament rises up and divides itself, generally three-forked, atthe length of one millimetre, into several series of branchlets.The forked branches of the last series bear under their points,which are mostly capillary, short erectlittle ramuli, and these, with whichthe ends of the principal branches articulateon their somewhat broad tops,several spores and conidia, near oneanother; about fifteen to twenty areformed at the end of each little ramulus.The peculiarities and variationswhich so often appear in theramification need not be discussedhere. After the articulation of the conidia, their bearers sinktogether by degrees, and are quite destroyed. The ripe conidiaare round like a ball, their surface is scarcely coloured, and almostwholly smooth. These conidioid forms were at first describedas a separate species under the name ofBotrytis Jonesii. How,then, do they belong to theMucor?[t] That they appear gregariouslyis as little proof of an original relation to one another,here as elsewhere. Attempts to prove that the conidia and sporangia-bearersoriginate on one and the same mycelium filamentmay possibly hereafter succeed. Till now this has not been the case,[Pg 54]and he who has ever tried to disentangle the mass of filamentswhich exuberantly covers the substratum of aMucor vegetation,which has reached so far as to form conidia, will not be surprisedthat all attempts have hitherto proved abortive. The suspicionof the connection founded on the gregariously springing up, andexternal resemblance, is fully justified, if we sow the conidia in asuitable medium, for example, in a solution of sugar. Theyhere germinate and produce a mycelium which exactly resemblesthat of theMucor mucedo, and, above all, they producein profusion the typical sporangia of the same on itsbearers. The latter are till now alone reproductions of conidia-bearers,and have never been observed on mycelia which havegrown out of conidia.

Fig. 32.—Small portion ofBotrytis Jonesii.

These phenomena of development appear in theMucor whenit dwells on a damp substance, which must naturally containthe necessary nourishment for it, and is exposed to the atmosphericair. Its mycelium represents at first strong branchedutricles without partitions; the branches are of the higherorder, mostly divided into rich and very fine-pointed ramuli.In old mycelium, and also in the sporangia-bearers, the contentsof which are mostly used for the formation of spores, andthe substratum of which is exhausted for our fungus, shortstationary pieces, filled with protoplasm, are very often formedinto cells through partitions in order to produce spores, thatis, grow to a new fruitful mycelium. These cells are calledgemmules, brooding cells, and resemble such vegetable buds andsprouts of foliaceous plants which remain capable of developmentafter the organs of vegetation are dead, in order to grow,under suitable circumstances, to new vegetating plants, as, forexample, the bulbs of onions, &c.

If we bring a vegetating mycelium ofMucor mucedo into amedium which contains the necessary nourishment for it, butexcluded from the free air, the formation of sporangia takes placevery sparingly or not at all, but that of gemmules is very abundant.Single interstitial pieces of the ramuli, or even wholesystems of branches, are quite filled with a rich greasy protoplasm;the short pieces and ends are bound by partitions which[Pg 55]form particular, often tun-like or globular cells; the longer onesare changed, through the formation of cross partitions, intochains of similar cells; the latter often attain by degrees strong,thick walls, and their greasy contents often pass into innumerabledrops of a very regular globular form and of equal size. Similarappearances show themselves after the sowing of spores, whichare capable of germinating in the medium already described,from which the air is excluded. Either short germinatingutricles shoot forth, which soon form themselves into rows ofgemmules, or the spores swell to large round bladders filledwith protoplasm, and shoot forth on various parts of theirsurface innumerable protuberances, which, fixing themselveswith a narrow basis, soon become round vesiculate cells, and onwhich the same sprouts which caused their production are repeated,formations which remind us of the fungus of fermentationcalled globular yeast. Among all the known forms ofgemmules we find a variety which are intermediate, all of whichshow, when brought into a normal condition of development,the same proportion, and the same germination, as those we firstdescribed.

We have detailed rather at length the structure and developmentof one of the most common of the Mucors, which willserve as an illustration of the order. Other distinctions theremay be which are of more interest as defining the limits ofgenera, except such as may be noticed when we come to writemore specially of reproduction.

Ascomycetes.—Passing now to theAscomycetes, which areespecially rich in genera and species, we must first, and but superficially,allude toTuberacei, an order of sporidiiferous fungi ofsubterranean habit, and rather peculiar structure.[u] In this orderan external stratum of cells forms a kind of perithecium, whichis more or less developed in different genera. This encloses thehymenium, which is sinuous, contorted, and twisted, often forminglacunæ. The hymenium in some genera consists of elongated,nearly cylindrical asci, enclosing a definite number of sporidia;in the true truffles and their immediate allies, the asci are broad[Pg 56]sacs, containing very large and beautiful, often coloured, sporidia.These latter have either a smooth, warted, spinulose, or lacunoseepispore, and, as will be seen from the figures in Tulasne’sMonograph,[v] or those in the last volume of Corda’s great work,[w]are attractive microscopical objects. In some cases, it is notdifficult to detect paraphyses, but in others they would seem tobe entirely absent. A comparatively large number have beendiscovered and recorded in Great Britain,[x] but of those noneare more suitable for study of general structure than the ordinarytruffle of the markets.

The structure of the remaining Ascomycetes can be studiedunder two groups,i.e., the fleshy Ascomycetes, or, as they havebeen termed, the Discomycetes, and the hard, or carbonaceous Ascomycetes,sometimes called the Pyrenomycetes. Neither of thesenames gives an accurate idea of the distinctions between the twogroups, in the former of which the discoid form is not universal,and the latter contains somewhat fleshy forms. But in the Discomycetesthe hymenium soon becomes more or less exposed,and in the latter it is enclosed in a perithecium. The Discomycetesare of two kinds, the pileate and the cup-shaped. Of thepileate such a genus asGyromitra orHelvella is, in a certainsense, analogous to the Agarics amongstHymenomycetes, with asuperior instead of an inferior hymenium, and enclosed, notnaked, spores. Again,Geoglossum is somewhat analogous toClavaria. Amongst the cup-shaped,Peziza is an AscomycetousCyphella. But these are perhaps more fanciful than realanalogies.

Recently Boudier has examined one group of the cup-shapedDiscomycetes, theAscobolei, and, by making a somewhat free useof his Memoir,[y] we may arrive at a general idea of the structurein the cupulate Discomycetes. They present themselves at[Pg 57]first under the form of a small rounded globule, and almostentirely cellular. This small globule, the commencementof the receptacle, is not long in increasing, preserving itsrounded form up to the development of the asci. At thisperiod, under the influence of the rapid growth of these organs,it soon produces at its summit a fissure of the external membrane,which becomes a more marked depression in the marginatespecies. The receptacle thus formed increases rapidly,becomes plane, more convex, or more or less undulated at themargin, if at all of large size. Fixed to the place where it isgenerated by some more or less abundant mycelioid filaments, thereceptacle becomes somewhat cup-shaped and either stipitate orsessile, composed of the receptacle proper and the hymenium.

Fig. 33.—Section of cup ofAscobolus.a. External cells.b. Secondary layer.c. Subhymenial tissue (Janczenski).

The receptacle proper comprehends the subhymenial tissue,the parenchyma, and the external membrane. The subhymenialtissue is composed of small compact cells, forming generallya more coloured and dense stratum, the superior cells of whichgive rise to the asci and paraphyses. The parenchyma is seatedbeneath this, and is generally of interlaced filaments, of a looserconsistency than the preceding, united by intermediate cellules.The external membrane, which envelopes the parenchyma, andlimits the hymenium, differs from the preceding by the cellsoften being polyhedric, sometimes transverse, and united together,and sometimes separable. Externally it is sometimessmooth, and sometimes granular or hairy.

The hymenium is, however, the most, important part, consistingof (1) the paraphyses, (2) the asci, and sometimes (3)an investing mucilage. The asci are always present, the paraphysesare sometimes rare, and the mucilage in many casesseems to be entirely wanting.

The paraphyses, which are formed at the first commencementof the receptacle, are at first very short, but soon elongate, andbecome wholly developed before the appearance of the asci.They are linear, sometimes branched and sometimes simple,often more or less thickened at their tips; almost always theycontain within them some oleaginous granules, either coloured orcolourless. Their special function seems still somewhat obscure,and Boudier suggests that they may be excitatory organs forthe dehiscence of the asci. However this may be, some mycologistsare of opinion that, at least in some of the Ascomycetes,the paraphyses are abortive asci, or, at any rate, that abortiveasci mixed with the paraphyses cannot be distinguished fromthem.

The mucilage forms itself almost at the same time as theparaphyses, and previous to the formation of the asci. Thissubstance appears as a colourless or yellowish mucilage, whichenvelopes the paraphyses and asci, and so covers the hymeniumwith a shining coat.

The asci appear first at the base of the paraphyses, under theform of oblong cells, filled with colourless protoplasm. By rapidgrowth, they soon attain a considerable size and fulness, theprotoplasm being gradually absorbed by the sporidia, the firstindication of which is always the central nucleus. The mucilagealso partly disappears, and the asci, attaining their maturity,become quite distinct, each enclosing its sporidia. But beforethey take their complete growth they detach themselves fromthe subhymenial tissue, and being attenuated towards their base,are forced upwards by pressure of the younger asci, to, and insome instances beyond, the upper surface of the disc. Thisphenomenon commences during the night, and continues duringthe night and all the morning. It attains its height at mid-day,and it is then that the slightest breath of air, the slightest[Pg 59]movement, suffices to cause dehiscence, which is generallyfollowed by a scarcely perceptible contractile motion of thereceptacle.

Fig. 34.—Asci, sporidia, and paraphyses ofAscobolus (Boudier).

There is manifestly a succession in formation and maturity ofthe asci in a receptacle. In the trueAscobolei, in which thesporidia are coloured, this may be more distinctlyseen. At first some thin projectingpoints appear upon the disc, the next daythey are more numerous, and become moreand more so on following days, so as torender the disc almost covered with raisedblack or crystalline points;[z] these afterwardsdiminish day by day, until they ultimatelycease. The asci, after separationfrom the subhymenial tissue, continue tolengthen, or it may be that their elasticitypermits of extension, during expulsion.Boudier considers that an amount of elasticityis certain, because he has seen anascus arrive at maturity, eject its spores,and then make a sharp and considerablemovement of retraction, then the ascus returnedagain, immediately towards its previouslimits, always with a reduction in thenumber of its contained sporidia.

The dehiscence of the asci takes place intheAscobolei, in some species ofPeziza,Morchella,Helvella, andVerpa, by meansof an apical operculum, and in otherPezizæ,Helotium,Geoglossum,Leotia,Mitrula, &c.,by a fissure of the ascus. This operculummay be the more readily seen when the ascus is coloured by adrop of tincture of iodine.

The sporidia are usually four or eight, or some multiple ofthat number, in each ascus, rarely four, most commonly eight.At a fixed time the protoplasm, which at first filled the asci, disappears[Pg 60]or is absorbed in a mucilaginous matter, which occupiesits place, in the midst of which is a small nucleus, which is therudiment of the first spore; other spores are formed consecutively,and then the substance separates into as many sections as thereare sporidia. From this period each sporidium seems to have aseparate existence. All have a nucleus, which is scarcely visible,often slightly granular, but which is quite distinct from theoleaginous sporidioles so frequent amongst the Discomycetes,and which are sometimes called by the same name. The sporidiaare at first a little smaller than when mature, and are surroundedby mucilage. After this period the sporidia lose theirnebulous granulations, whilst still preserving their nucleus; theiroutlines are distinct, and, amongst the trueAscobolei, commenceacquiring a rosy colour, the first intimation of maturity. Thiscolour manifests itself rapidly, accumulating exclusively uponthe epispore, which becomes of a deep rose, then violet, andfinally violet blue, so deep as sometimes to appear quite black.There are some modifications in this coloration, since, in somespecies, it passes from a vinous red to grey, then to black, orfrom rose-violet to brown.

The epispore acquires a waxy consistence by this pigmentation,so that it may be detached in granules. It is to this particularconsistency of the epispore that the cracks so frequent inthe coloured sporidia ofAscobolus are due, through contractionof the epispore. As they approach maturity, the sporidia accumulatetowards the apex of the asci, and finally escape in themanner already indicated.

In all essential particulars there is a great similarity in thestructure of the other Discomycetes, especially in their reproductivesystem. In most of them coloured sporidia are rare. Insome the receptacle is pileate, clavate, or inflated, whilst inStictis it is very much reduced, and in the lowest form of all,Ascomyces, it is entirely absent. In thePhacidiacei, the structureis very similar to that of theElvellacei, whilst theHysteriacei,with greater affinities with the latter, still tend towardsthePyrenomycetes by the more horny nature of the receptacle,and the greater tendency of the hymenium to remain closed, at[Pg 61]least when dry. In some species ofHysterium, the sporidia areremarkably fine. M. Duby[AA] has subjected this group to examination,and M. Tulasne partly so.[AB]

Sphæriacei.—In this group there is considerable variation,within certain limits. It contains an immense number ofspecies, and these are daily being augmented. The generalfeature in all is the presence of a perithecium, which containsand encloses the hymenium, and at length opening by a poreor ostiolum at the apex. In some the perithecia are simple, inothers compound; in some immersed in a stroma, in othersfree; in some fleshy or waxy, in others carbonaceous, and inothers membranaceous. But in all there is this important differencefrom the Ascomycetes we have already had under consideration,that the hymenium is never exposed. The peritheciumconsists usually of an externallayer of cellular structure, which iseither smooth or hairy, usually blackish,and an internal stratum of lesscompact cells, which give rise to thehymenium.

Fig. 35.—Perithecium ofSphæria and Section.

As in theDiscomycetes, the hymeniumconsists of asci, paraphyses, and mucilage, but the wholeforms a less compact and more gelatinous mass within the perithecium.The formation and growth of the asci and sporidiadiffer little from what we have described, and when mature theasci dehisce, and the sporidia alone are ejected from the ostiolum.We are not aware that operculate asci have yet been detected.It has been shown in some instances, and suspected in others,that certain moulds, formerly classed withMucedines andDematiei,especially in the genusHelminthosporium, bear the conidiaof species ofSphæria, so that this may be regarded as one formof fruit.

Perithecia, very similar externally to those ofSphæria, butcontaining spores borne on slender pedicels and not enclosed inasci, have had their relations to certain species ofSphæria indicated,[Pg 62]and these are no longer regarded so much as species ofHendersonia orDiplodia as the pycnidia ofSphæria. Other andmore minute perithecia, containing minute, slender stylospores ingreat numbers, formerly classed withAposphæria,Phoma, &c., butare now recognized as spermogonia containing the spermatia ofSphæriæ. How these influence each other, when and underwhat circumstances the spermatia are instrumental in impregnationof the sporidia, is still matter of mystery. It is clear, however,that in all these conidia, macrospores, microspores, andsome spermatia, or by whatever names they may be called, thereexists a power of germination. Tulasne has indicated in someinstances five or six forms of fruit as belonging to one fungus,of which the highest and most perfect condition is a species ofSphæria.

Fig. 36.—Uncinula adunca.

Perisporiacei.—Except in the perithecia rupturing irregularly,and not dehiscing by a pore, some ofthe genera in this group differ little instructure from theSphæriacei. On theother hand, theErysiphei present importantand very interesting features. Theyoccur chiefly on the green parts of growingplants. At first there is a more orless profuse white mycelium.[AC] Thisgives rise to chains of conidia (Oidium),and afterwards small sphæroid projections appear at certainpoints on the mycelium. These enlarge, take an orange colour,ultimately passing into brown, and then nearly black. Externallythese perithecia are usually furnished with long, spreading,intertwined, or branching appendages, sometimes beautifullybranched or hooked at their tips. In the interior of the receptacles,pear-shaped or ovate asci are formed in clusters, attachedtogether at the base, and containing two or more hyalinesporidia. Other forms of fruit have also been observed onthe same mycelium. In an exotic genus,Meliola, the fulcra, orappendages, as well as the mycelium, are black, otherwise it[Pg 63]is very analogous to such a genus ofErysiphei asMicrosphæria.InChætomium, the perithecia bristle with rigid, dark-colouredhairs, and the sporidia are coloured. Our limits, however, willnot permit of further elucidation of the complex and variedstructure to be found amongst fungi.[AD]

A work of this kind could not be considered complete withoutsome account of the systematic arrangement or classificationwhich these plants receive at the hands of botanists. It wouldhardly avail to enter too minutely into details, yet sufficientshould be attempted to enable the reader to comprehend thevalue and relations of the different groups into which fungi aredivided. The arrangement generally adopted is based uponthe “Systema Mycologicum” of Fries, as modified to meet therequirements of more recent microscopical researches by Berkeleyin his “Introduction,”[A] and adopted in Lindley’s “VegetableKingdom.” Another arrangement was proposed by Professorde Bary,[B] but it has never met with general acceptance.

In the arrangement to which we have alluded, all fungi aredivided into two primary sections, having reference to the modein which the fructification is produced. In one section, thespores (which occupy nearly the same position, and performsimilar functions, to the seeds of higher plants) are naked; thatis, they are produced on spicules, and are not enclosed in cystsor capsules. This section is calledSporifera, or spore-bearing,because, by general consent, the termspore is limited in fungito such germ-cells as are not produced in cysts. The secondsection is termedSporidiifera, or sporidia-bearing, because inlike manner the termsporidia is limited to such germ-cells as[Pg 65]are produced in cells or cysts. These cysts are respectivelyknown assporangia, andasci orthecæ. The true meaning andvalue of these divisions will be better comprehended when wehave detailed the characters of the families composing these twodivisions.

First, then, the sectionSporifera contains four families, in twoof which a hymenium is present, and in two there is no properhymenium. The termhymenium is employed to represent amore or less expanded surface, on which the fructification isproduced, and is, in fact, the fruit-bearing surface. When nosuch surface is present, the fruit is borne on threads, proceedingdirect from the root-like filaments of the mycelium, or an intermediatekind of cushion or stroma. The two families in whichan hymenium is present are calledHymenomycetes andGasteromycetes.In the former, the hymenium is exposed; in the latter, itis at first enclosed. We must examine each of these separately.

The common mushroom may be accepted, by way of illustration,as a type of the familyHymenomycetes, in which thehymenium is exposed, and is, in fact, the most noticeablefeature in the family from which its name is derived. Thepileus or cap bears on its under surface radiating plates or gills,consisting of the hymenium, over which are thickly scatteredthe basidia, each surmounted by four spicules, and on eachspicule a spore. When mature, these spores fall freely upon theground beneath, imparting to it the general colour of the spores.But it must be observed that the hymenium takes the form ofgill-plates in only one order ofHymenomycetes, namely, theAgaricini; and here, as inCantharellus, the hymenium is sometimesspread over prominent veins rather than gills. Stillfurther divergence is manifest in thePolyporei, in which orderthe hymenium lines the inner surface of pores or tubes, whichare normally on the under side of the pileus. Both these ordersinclude an immense number of species, the former more or lessfleshy, the latter more or less tough and leathery. There arestill other forms and orders in this family, as theHydnei, inwhich the hymenium clothes the surface of prickles or spines,and theAuricularini, in which the hymenium is entirely or[Pg 66]almost even. In the two remaining orders, there is a still furtherdivergence from the mushroom form. In the one calledClavariei,the entire fungus is either simply cylindrical or club-shaped, orit is very much branched and ramified. Whatever form thefungus assumes, the hymenium covers the whole exposed surface.In theTremellini, a peculiar structure prevails, which at firstseems to agree but little with the preceding. The whole plantis gelatinous when fresh, lobed and convolute, often brain-like,and varying in size, according to species, from that of a pin’shead to that of a man’s head. Threads and sporophores areimbedded in the gelatinous substance,[C] so that the fertile threadsare in reality not compacted into a truehymenium. With this introduction wemay state that the technical charactersof the family are thus expressed:—

Hymenium free, mostly naked, or, ifenclosed at first, soon exposed; sporesnaked, mostly quaternate, on distinctspicules =Hymenomycetes.

Fig. 37.—Agaricus nudus.

In this family some mycologists believethat fungi attain the highest formof development of which they are capable,whilst others contend that thefructification of theAscomycetes is moreperfect, and that some of the noblest species, such as the pileateforms, are entitled to the first rank. The morel is a familiarexample. Whatever may be said on this point, it is incontrovertiblethat the noblest and most attractive, as well as thelargest, forms are classed under theHymenomycetes.

InGasteromycetes, the second family, a true hymenium isalso present, but instead of being exposed it is for a long timeenclosed in an outer peridium or sac, until the spores are fullymatured, or the fungus is beginning to decay. The commonpuff-ball (Lycoperdon) is well known, and will illustrate theprincipal feature of the family. Externally there is a tough[Pg 67]coat or peridium, which is at first pale, but ultimately becomesbrown. Internally is at first a cream-coloured, then greenish,cellular mass, consisting of the sinuated hymenium and youngspores, which at length, and when the spores are fully maturedbecome brownish and dusty, the hymenium being broken upinto threads, and the spores become free. In earlier stages,and before the hymenium is ruptured, the spores have beenfound to harmonize with those ofHymenomycetes in their modeof production, since basidia are present surmounted each byfour spicules, and each spicule normally surmounted by aspore.[D] Here is, therefore, a cellular hymenium bearing quaternaryspores, but, instead of being exposed, this hymeniumis wholly enclosed within an external sac or peridium, whichis not ruptured until the spores are fully matured, and thehymenium is resolved into threads, together forming a pulverulentmass. It must, however, be borne in mind, that inonly some of the orders composing this family is the hymeniumthus evanescent, in others being more or less permanent, andthis has led naturally enough to the recognition of two sub-families,in one of which the hymenium is more or less permanent,thus following the Hymenomycetous type; and in theother, the hymenium is evanescent, and the dusty mass of sporestends more towards theConiomycetes, this being characterizedas the coniospermous (or dusty-spored) sub-family.

The first sub-family includes, first of all, theHypogæi, or subterraneanspecies. And here again it becomes necessary to remindthe reader that all subterranean fungi are not included inthis order, inasmuch as some, of which the truffle is an example,are sporidiiferous, developing their sporidia in asci. Tothese allusion must hereafter be made. In theHypogæi, thehymenium is permanent and convoluted, leaving numerousminute irregular cavities, in which the spores are produced on[Pg 68]sporophores. When specimens are very old and decaying, theinterior may become pulverulent or deliquescent. The structureof subterranean fungi attracted the attention of Messrs. Tulasne,and led to the production of a splendid monograph on thesubject.[E] Another order belonging to this sub-family is thePhalloidei, in which the volva or peridium is ruptured whilstthe plant is still immature, and the hymenium when maturebecomes deliquescent. Not only are some members of thisorder most singular in appearance, but they possess an odourso fœtid as to be unapproached in this property by any othervegetable production.[F] In this order, the inner stratum of theinvesting volva is gelatinous. When still young, and previousto the rupture of the volva, the hymenium presents sinuouscavities in which the spores are produced on spicules, after themanner ofHymenomycetes.[G]Nidulariacei is a somewhat aberrantorder, presenting a peculiar structure. The peridium consistsof two or three coats, and bursts at the apex, eitherirregularly or in a stellate manner, or by the separation ofa little lid. Within the cavity are contained one or moresecondary receptacles, which are either free or attached byelastic threads to the common receptacle. Ultimately thesecondary receptacles are hollow, and spores are producedin the interior, borne on spicules.[H] The appearance in somegenera as of a little bird’s-nest containing eggs has furnishedthe name to the order.

Fig. 38.—Scleroderma vulgare, Fr.

The second sub-family contains the coniospermous puff-balls,and includes two orders, in which the most readily distinguishablefeature is the cellular condition of the entire plant, in itsearlier stages, in theTrichogastres, and the gelatinous conditionof the early state of theMyxogastres. Both are ultimatelyresolved internally into a dusty mass of threads and spores.[Pg 69]In the former, the peridium is either single or double, occasionallyborne on a stem, but usually sessile. InGeaster,the “starry puff-balls,” the outer peridium divides intoseveral lobes, which fall back in a stellate manner, and exposethe inner peridium, like a ball in the centre. InPolysaccum,the interior is divided into numerouscells, filled with secondary peridia. Themode of spore-production has alreadybeen alluded to in our remarks onLycoperdon.All the species are large, ascompared with those of the followingsub-family, and one species ofLycoperdonattains an enormous size. Onespecimen recorded in the “Gardener’sChronicle” was three feet four inchesin circumference, and weighed nearlyten pounds. In theMyxogastres, the early stage has been thesubject of much controversy. The gelatinous condition presentsphenomena so unlike anything previously recorded in plants,that one learned professor[I] did not hesitate to propose theirexclusion from the vegetable, and recognition in the animal,kingdom as associates of the Gregarines. When mature, thespores and threads so much resemble those of theTrichogastres,and the little plants themselves are so veritably miniature puff-balls,that the theory of their animal nature did not meet witha ready acceptance, and is now virtually abandoned. The charactersof the family we have thus briefly reviewed are terselystated, as—

Hymenium more or less permanently concealed, consisting inmost cases of closely-packed cells, of which the fertile ones bearnaked spores on distinct spicules, exposed only by the rupture ordecay of the investing coat or peridium =Gasteromycetes.

Fig. 39.—Ceuthospora phacidioides (Greville).

We come now to the second section of theSporifera, inwhich no definite hymenium is present. And here we findalso two families, in one of which the dusty spores are the[Pg 70]prominent feature, and hence termedConiomycetes; the other,in which the threads are most noticeable, isHyphomycetes.In the former of these, the reproductive system seems to preponderateso much over the vegetative, that the fungus appearsto be all spores. The mycelium is often nearly obsolete, andthe short pedicels so evanescent, that a rusty or sooty powderrepresents the mature fungus, infesting the green parts of livingplants. This is more especially true of one or two orders. Itwill be most convenient to recognize two artificial sub-familiesfor the purpose of illustration, in one of which the species aredeveloped on living, and in the other on dead, plants. We willcommence with the latter, recognizing first those which aredeveloped beneath the cuticle, and then those which are superficial.Of the sub-cuticular, two orders may be named as therepresentatives of this group in Britain, these are theSphæronemei,in which the spores are contained in a more or less perfectperithecium, and theMelanconiei, in which there is manifestlynone. The first of these is analogous to theSphæriacei ofAscomycetousfungi, and probably consists largely of spermogoniaof known species ofSphæria, the relations of which have nothitherto been traced. The spores are produced on slenderthreads springing from the inner wall of the perithecium, and,when mature, are expelled from an orifice at the apex. This isthe normal condition, to which there are some exceptions. IntheMelanconiei, there is no true perithecium, but the spores areproduced in like manner upon a kind of stroma or cushion[Pg 71]formed from the mycelium, and, when mature, are expelledthrough a rupture of the cuticle beneath which they are generated,often issuing in long gelatinous tendrils. Here, again,the majority of what were formerly regarded as distinct specieshave been found, or suspected, to be forms of higher fungi. TheTorulacei represent the superficial fungi of this family, and theseconsist of a more or less developed mycelium, which gives riseto fertile threads, which, by constriction and division, matureinto moniliform chains of spores. The species mostly appearas blackish velvety patches or stains on the stems of herbaceousplants and on old weathered wood.

Much interest attaches to the other sub-family ofConiomycetes,in which the species are produced for the most part on livingplants. So much has been discovered during recent years of thepolymorphism which subsists amongst the species in this section,that any detailed classification can only be regarded as provisional.Hence we shall proceed here upon the suppositionthat we are dealing with autonomous species. In the first place,we must recognize a small section in which a kind of cellularperidium is present. This is theÆcidiacei, or order of “clustercups.” The majority of species are very beautiful objects underthe microscope; the peridia are distinctly cellular, and white orpallid, produced beneath the cuticle, through which they burst,and, rupturing at the apex, in one genus in a stellate manner,so that the teeth, becoming reflexed, resemble delicate fringedcups, with the orange, golden, brown, or whitish spores orpseudospores nestling in the interior.[J] These pseudosporesare at first produced in chains, but ultimately separate. Inmany cases these cups are either accompanied or preceded byspermogonia. In two other orders there is no peridium. IntheCæomacei, the pseudospores are more or less globose orovate, sometimes laterally compressed and simple; and inPucciniæi, they are elongated, often subfusiform and septate.In both, the pseudospores are produced in tufts or clustersdirect from the mycelium. The Cæomacei might again be subdivided[Pg 72]intoUstilagines[K] andUredines.[L] In the former, thepseudospores are mostly dingy brown or blackish, and in thelatter more brightly coloured, often yellowish. TheUstilaginesinclude the smuts and bunt of corn-plants, theUredinesinclude the red rusts of wheat and grasses. In some of thespecies included in the latter, two forms of fruit are found.InMelampsora, the summer pseudospores are yellow, globose,and were formerly classed as a species ofLecythea, whilstthe winter pseudospores are brownish, elongated, wedge-shapedby compression, and compact. ThePucciniæi[M] differprimarily in the septate pseudospores, which in one genus(Puccinia) are uniseptate; inTriphragmium, they are biseptate;inPhragmidium, multiseptate; and inXenodochus, moniliform,breaking up into distinct articulations. It is probable that, inall of these, as is known to be the case in most, the septatepseudospores are preceded or accompanied by simple pseudospores,to which they are mysteriously related. There is stillanother, somewhat singular, group usually associated with thePucciniæi, in which the septate pseudospores are immersed ingelatin, so that in many features the species seem to approachtheTremellini. This group includes two or three genera, thetype of which will be found inPodisoma.[N] These fungi areparasitic on living junipers in Britain and North America,appearing year after year upon the same gouty swellings of thebranches, in clavate or horn-shaped gelatinous processes of ayellowish or orange colour. Anomalous as it may at first sightappear to include these tremelloid forms with the dust-like fungi,their relations will on closer examination be more fully appreciated,when the form of pseudospores, mode of germination, andother features are taken into consideration, especially whencompared withPodisoma Ellisii, already alluded to. This familyis technically characterized as,—

Distinct hymenium none. Pseudospores either solitary or concatenate,produced on the tips of generally short threads, whichare either naked or contained in a perithecium, rarely compactedinto a gelatinous mass, at length producing minute spores =Coniomycetes.

The last family of the sporifera isHyphomycetes, in which thethreads are conspicuously developed. These are what are morecommonly called “moulds,” including some of the most elegantand delicate of microscopic forms. It is true of many of these,as well as of theConiomycetes, that they are only conidial formsof higher fungi; but there will remain a very large number ofspecies which, as far as present knowledge extends, must be acceptedas autonomous. In this family, we may again recognizethree subdivisions, in one of which the threads are more or lesscompacted into a common stem, in another the threads are free,and in the third the threads can scarcely be distinguished fromthe mycelium. It is this latter group which unites theHyphomyceteswith theConiomycetes, the affinities being increased by thegreat profusion with which the spores are developed. The firstgroup, in which the fertile threads are united so as to form acompound stem, consists of two small orders, theIsariacei and theStilbacei, in the former of which the spores are dry, and in thelatter somewhat gelatinous. Many of the species closely imitateforms met with in theHymenomycetes, such asClavaria; and,in the genusIsaria, it is almost beyond doubt that the speciesfound on dead insects, moths, spiders, flies, ants, &c., are merelythe conidiophores of species ofTorrubia.[O]

The second group is by far the largest, most typical, andattractive in this family. It contains the black moulds andwhite moulds, technically known as theDematiei and theMucedines. In the first, the threads are more or less corticated,that is, the stem has a distinct investing membrane, which peelsoff like a bark; and the threads, often also the spores, are dark-coloured,as if charred or scorched. In many cases, the sporesare highly developed, large, multiseptate, and nucleate, and seldom[Pg 74]are spores and threads colourless or of bright tints. IntheMucedines, on the contrary, the threads are never coated,seldom dingy, mostly white or of pure colours, and the sporeshave less a tendency to extra development or multiplex septation.In some genera, as inPeronospora for instance,[P] asecondary fruit is produced in the form ofresting spores from the mycelium; andthese generate zoospores as well as theprimary spores, similar to those commoninAlgæ. This latter genus is very destructiveto growing plants, one speciesbeing the chief agent in the potato disease,and another no less destructive to crops ofonions. The vine disease is produced by aspecies ofOidium, which is also classedwithMucedines, but which is really theconidiiferous form ofErysiphe. In other genera, the majorityof species are developed on decaying plants, so that, with theexception of the two genera mentioned, theHyphomycetes exerta much less baneful influence on vegetation than theConiomycetes.The last section, including theSepedoniei, has beenalready cited as remarkable for the suppression of the threads,which are scarcely to be distinguished from the mycelium; thespores are profuse, nestling on the floccose mycelium; whilstin theTrichodermacei, the spores are invested by the threads, asif enclosed in a sort of false peridium. A summary of thecharacters of the family may therefore be thus briefly expressed:—

Filamentous; fertile threads naked, for the most part free orloosely compacted, simple or branched, bearing the spores at theirapices, rarely more closely packed, so as to form a distinct commonstem =Hyphomycetes.

Fig. 40.—Rhopalomyces candidus.

Having thus disposed of theSporifera, we must advertto the two families ofSporidiifera. As more closely relatedto theHyphomycetes, the first of these to be noticed is the[Pg 75]Physomycetes, in which there is no proper hymenium, and thethreads proceeding from the mycelium bear vesicles containingan indefinite number of sporidia. The fertile threads areeither free or only slightly felted. In the orderAntennariei, thethreads are black and moniliform, more or less felted, bearingirregular sporangia. A common fungus namedZasmidiumcellare, found in cellars, and incrusting old wine bottles, aswith a blackened felt, belongs to this order. The larger andmore highly-developed order,Mucorini, differs in the threads,which are simple or branched, being free,erect, and bearing the sporangia at the tipsof the thread, or branches. Some of thespecies bear great external resemblance toMucedines until the fruit is examined, whenthe fructifying heads, commonly globose orovate, are found to be delicate transparentvesicles, enclosing a large number of minutesporidia; when mature, the sporangia burstand the sporidia are set free. In some species,it has long been known that a sort ofconjugation takes place between opposite threads, which resultsin the formation of a sporangium.[Q] None of these species aredestructive to vegetation, appearing only upon decaying, andnot upon living, plants. A state approaching putrescence seemsto be essential to their vigorous development. The followingcharacters may be compared with those of the family precedingit:—

Filamentous, threads free or only slightly felted, bearing vesicles,which contain indefinite sporidia =Physomycetes.

Fig. 41.—Mucor caninus.

In the last family, theAscomycetes, we shall meet with avery great variety of forms, all agreeing in producing sporidiacontained in certain cells called asci, which are produced fromthe hymenium. In some of these, the asci are evanescent,but in the greater number are permanent. InOnygenei, thereceptacle is either club-shaped or somewhat globose, and the[Pg 76]peridium is filled with branched threads, which produce asci of avery evanescent character, leaving the pulverulent sporidia tofill the central cavity. The species are all small, and singular fortheir habit of affecting animal substances, otherwise they areof little importance. ThePerisporiacei, on the other hand, arevery destructive of vegetation, being produced, in the majorityof cases, on the green parts of growing plants. To this orderthe hop mildew, rose mildew, and pea mildew belong. Themycelium is often very much developed, and in the case of themaple, pea, hop, and some others, it covers the parts attackedwith a thick white coating, so that from a distance the leavesappear to have been whitewashed. Seated on the mycelium, atthe first as little orange points, are the perithecia, which enlargeand become nearly black. In some species, very elegant whitishappendages radiate from the sides of the perithecia, the variationsin which aid in the discrimination of species. The peritheciacontain pear-shaped asci, which spring from the base and enclosea definite number of sporidia.[R] The asci themselves are soondissolved. Simultaneously with the development of sporidia,other reproductive bodies are produced direct from the mycelium,and in some species as many as five different kinds of reproductivebodies have been traced. The features to be remembered inPerisporiacei, as forming the basis of their classification, are, thatthe asci are saccate, springing from the base of the perithecia,and are soon absorbed. Also that the perithecia themselves arenot perforated at the apex.

The four remaining orders, though large, can be easily characterized.InTuberacei, all the species are subterranean, and thehymenium is mostly sinuated. InElvellacei, the substance ismore or less fleshy, and the hymenium is exposed. InPhacidiacei,the substance is hard or leathery, and the hymenium issoon exposed. And inSphæriacei, although the substance isvariable, the hymenium is never exposed, being enclosed inperithecia with a distinct opening at the apex, through whichthe mature spores escape. Each of these four orders must be[Pg 77]examined more in detail. TheTuberacei, or subterraneanAscomycetes, are analogous to theHypogæi of theGasteromycetes.The truffle is a familiar and highly prized example. There is akind of outer peridium, and the interior consists of a fleshyhymenium, more or less convoluted, sometimes sinuous and confluent,so as to leave only minute elongated and irregular cavities,and sometimes none at all, the two opposing faces of thehymenium meeting and coalescing.[S] Certain privileged cellsof the hymenium swell, and ultimately become asci, enclosing adefinite number of sporidia. The sporidia in many cases arelarge, reticulated, echinulate or verrucose, and mostly somewhatglobose. In the genusElaphomyces, the asci are more thancommonly diffluent.

TheElvellacei are fleshy in substance, or somewhat waxy,sometimes tremelloid. There is no peridium, but the hymeniumis always exposed. There is a great variety of forms, somebeing pileate, and others cup-shaped, as there is also a greatvariation in size, from the minutePeziza, small as a grain ofsand, to the largeHelvella gigas, which equals in dimensionsthe head of a child. In the pileate forms, the stromais fleshy and highly developed; in the cup-shaped, it isreduced to the external cells of the cup which enclose thehymenium. The hymenium itself consists of elongated fertilecells, or asci, mixed with linear thread-like barren cells, calledparaphyses, which are regarded by some authors as barren asci.These are placed side by side in juxtaposition with the apexoutwards. Each ascus contains a definite number of sporidia,which are sometimes coloured. When mature, the asci explodeabove, and the sporidia may be seen escaping like a miniaturecloud of smoke in the light of the mid-day sun. The disc orsurface of the hymenium is often brightly coloured in the genusPeziza; tints of orange, red, and brown having the predominance.

InPhacidiacei, the substance is hard and leathery, intermediatebetween the fleshyElvellacei and the more horny of theSphæriacei.The perithecia are either orbicular or elongated, and the[Pg 78]hymenium soon becomes exposed. In some instances, there isa close affinity with theElvellacei, the exposed hymenium beingsimilar in structure, but in all the disc is at first closed. Inorbicular forms, the fissure takes place in a stellate manner fromthe centre, and the teeth are reflexed. In theHysteriacei, wherethe perithecia are elongated, the fissure takes place throughouttheir length. As a rule, the sporidia are more elongated, morecommonly septate, and more usually coloured, than inElvellacei.Only a few solitary instances occur of individual species thatare parasitic on living plants.

Fig. 42.—Sphæria aquila.

In theSphæriacei, the substance of the stroma (when present)and of the perithecia is variable,being between fleshy and waxyinNectriei, and tough, horny, sometimesbrittle, inHypoxylon. A perithecium,or cell excavated in thestroma which fulfils the functions ofa perithecium, is always present.The hymenium lines the inner wallsof the perithecium, and forms a gelatinousnucleus, consisting of asci andparaphyses. When fully mature, the asci are ruptured and thesporidia escape by a pore which occupies the apex of the perithecium.Sometimes the perithecia are solitary or scattered, andsometimes gregarious, whilst in other instances they are closelyaggregated and immersed in a stroma of variable size and form.Conidia, spermatia, pycnidia, &c., have been traced to and associatedwith some species, but the history of others is still obscure.Many of the coniomycetous forms grouped under theSphæronemeiare probably conditions of theSphæriacei, as are also theMelanconiei,and some of theHyphomycetes. A very common fungus,for instance, which is abundant on sticks and twigs, formingrosy or reddish pustules the size of a millet seed, formerlynamedTubercularia vulgaris, is known to be the conidia-bearingstroma of the sphæriaceous fungus,Nectria cinnabarina;[T] and so[Pg 79]with many others. The following are the technical charactersof the family:—

Fruit consisting of sporidia, mostly definite, contained in asci,springing from a naked or enclosed stratum of fructifying cellsand forming a hymenium or nucleus =Ascomycetes.

If the characters of the different families are borne in mind,there will be but little difficulty in assigning any fungus to theorder to which it belongs by means of the foregoing remarks.For more minute information, and for analytical tables of thefamilies, orders, and genera, we must refer the student to somespecial systematic work, which will present fewer difficulties, ifhe keeps in mind the distinctive features of the families.[U]

To assist in this we have given on the following page ananalytical arrangement of the families and orders, accordingto the system recognized and adopted in the present volume.It is, in all essential particulars, the method adopted in our“Handbook,” based on that of Berkeley’s “Introduction” and“Outlines.”

TABULAR ARRANGEMENT OF FAMILIES AND ORDERS.

The rigid utilitarian will hardly be satisfied with the shortcatalogue which can be furnished of the uses of fungi. Exceptingthose which are employed more or less for human food, veryfew are of any practical value in arts or medicine. It is truethat imperfect conditions of fungi exert a very important influenceon fermentation, and thus become useful; but, unfortunately,fungi have the reputation of being more destructive andoffensive than valuable or useful. Notwithstanding that a largenumber of species have from time to time been enumerated asedible, yet those commonly employed and recognized are veryfew in number, prejudice in many cases, and fear in others, militatingstrongly against additions to the number. In GreatBritain this is especially the case, and however advisable it maybe to exercise great care and caution in experimenting on untriedor doubtful species, it can only be regarded as prejudice whichprevents good, in fact, excellent, esculent species being moreextensively used, instead of allowing them to rot by thousandson the spots where they have grown. Poisonous species arealso plentiful, and no golden rule can be established by meansof which any one may detect at a glance good from bad,without that kind of knowledge which is applied to the discriminationof species. Yet, after all, the characters of halfa dozen good esculent fungi are acquired as easily as thedistinctions between half a dozen birds such as any ploughboycan discriminate.

The common mushroom (Agaricus campestris) is the best[83]known esculent, whether in its uncultivated or in a cultivatedstate. In Britain many thousands of people, notably the lowerclasses, will not recognize any other as fit for food, whilst inItaly the same classes have a strong prejudice against this veryspecies.[A] In Vienna, we found by personal experience that,although many others are eaten, it is this which has the mostuniversal preference, yet it appears but sparingly in the marketsas compared with others. In Hungary it does not enjoy byany means so good a reputation. In France and in Germanyit is a common article of consumption. The different varietiesfound, as the results of cultivation, present some variation incolour, scaliness of pileus, and other minor features, whilstremaining true to the constituent characters of the species.Although it is not our intention to enumerate here the botanicaldistinctions of the species to which we may call attention, yet,as mistakes (sometimes fatal) are often being recorded, in whichother fungi are confounded with this, we may be permitted ahint or two which should be remembered. The spores arepurple, the gills are at first delicate pink, afterwards purple;there is a permanent ring or collar round the stem, and it mustnot be sought in woods. Many accidents might have beenspared had these facts been remembered.

The meadow mushroom (Agaricus arvensis) is common inmeadows and lowland pastures, and is usually of a larger sizethan the preceding, with which it agrees in many particulars,and is sent in enormous quantities to Covent Garden, where itfrequently predominates overAgaricus campestris. Some personsprefer this, which has a stronger flavour, to the ordinary mushroom,and it is the species most commonly sold in the autumnin the streets of London and provincial towns. According toPersoon, it is preferred in France; and, in Hungary, it is consideredas a special gift from St. George. It has acquired inEngland the name of horse mushroom, from the enormous size[84]it sometimes attains. Withering mentions a specimen thatweighed fourteen pounds.[B]

One of the commonest (in our experience themost common)of all edible fungi in the public markets of Vienna is theHallimasche (Agaricus melleus), which in England enjoys nogood reputation for flavour or quality; indeed, Dr. Badhamcalls it “nauseous and disagreeable,” and adds that “not tobe poisonous is its only recommendation.” In Vienna it isemployed chiefly for making sauce; but we must confess thateven in this way, and with a prejudice in favour of Viennesecookery, our experience of it was not satisfactory. It is atbest a sorry substitute for the mushroom. In the summer andautumn this is a very common species in large tufts on oldstumps. In similar localities, and also in tufts, but neither solarge, nor so common,Agaricus fusipes is found. It is preferableto the foregoing as an esculent, and is easily recognized bythe spindle-shaped stem.

Agaricus rubescens, P., belongs to a very suspicious group offungi, in which the cap or pileus is commonly studded orsprinkled with paler warts, the remains of an investing volva.To this group the poisonous but splendid fly-agaric (Agaricusmuscarius) belongs. Notwithstanding its bad company, thisagaric has a good reputation, especially for making ketchup;and Cordier reports it as one of the most delicate mushroomsof the Lorraine.[C] Its name is derived from its tendency tobecome red when bruised.

The white variety of an allied species (Agaricus vaginatus)has been commended, and Dr. Badham says that it will be foundinferior to but few agarics in flavour.

A scaly-capped fungus (Agaricus procerus), with a slenderstem, called sometimes the parasol mushroom, from its habit, isan esteemed esculent. In Italy and France it is in high request,[85]and is included in the majority of continental works on theedible fungi.[D] In Austria, Germany, and Spain, it has special“vulgar” names, and is eaten in all these countries. It ismuch more collected in England than formerly, but deservesto be still better known. When once seen it can scarcely beconfounded with any other British species, save one of itsnearest allies, which partakes of its own good qualities (Agaricusrachodes), though not quite so good.

Agaricus prunulus, Scop., andAgaricus orcella, Badh., if theybe not forms of the same species (which Dr. Bull contends thatthey are not[E]), have also a good reputation as esculents. Theyare both neat, white agarics, with a mealy odour, growingrespectively in woods and open glades.Agaricus nebularis,Batsch, is a much larger species, found in woods, often in largegregarious patches amongst dead leaves, with a smoky mouse-colouredpileus, and profuse white spores. It is sometimes asmuch as five or six inches in diameter, with rather a faint odourand mild taste. On the continent, as well as in Britain, this isincluded amongst edible fungi. Still larger and more imposingis the magnificent white species,Agaricus maximus, Fr.,[F] whichis figured by Sowerby,[G] under the name ofAgaricus giganteus.It will attain a diameter of fourteen inches, with a stem, twoinches thick, and rather a strong odour.

A spring fungus, the true St. George’s mushroom,Agaricusgambosus, Fr., makes its appearance in pastures, usually growingin rings, in May and June, and is welcome to mycophagists fromits early growth, when esculent species are rare. It is highlyesteemed in France and Italy, so that when dried it will realizeas much as from twelve to fifteen shillings per pound. Guillarmodincludes it amongst Swiss esculents.[H] Professor Buckman[86]says that it is one of the earliest and best of English mushrooms,and others have endorsed his opinions, and Dr. Badhamin writing of it observes, that small baskets of them, when theyfirst appear in the spring in Italy, are sent as “presents tolawyers and fees to medical men.”

The closely allied species,Agaricus albellus,[I] D.C., has alsothe reputation of being edible, but it is so rare in England thatthis quality cannot be put to the test. The curious short-stemmedAgaricus brevipes, Bull,[J] has a similar reputation.

Two singularly fragrant species are also included amongst theesculent. These areAgaricus fragrans, Sow., andAgaricusodorus, Bull. Both have a sweet anise-like odour, which is persistentfor a long time. The former is pale tawny-coloured, nearlywhite, the latter of a dirty pale green. Both are white-spored,and although somewhat local, sufficient specimens ofAg. odorusmay be collected in the autumn for domestic use. We have theassurance of one who has often proved them that they constitutean exquisite dish.

A clear ivory-white fungus,Agaricus dealbatus, of which acrisped variety is occasionally found in great numbers, springingup on old mushroom beds in dense clusters, is very good eating,but rather deficient in the delicate aroma of some other species.The typical form is not uncommon on the ground in fir plantations.A more robust and larger species,Agaricus geotrupes,Bull, found on the borders of woods, often forming rings, bothin this country and in the United States, as well as on the continentof Europe, is recognized as esculent.

We may add to these three or four other species, in which thestem is lateral, and sometimes nearly obsolete. The largest andmost common is the oyster mushroom (Agaricus ostreatus,Jacq.[K]), so universally eaten, that it is included in almost everylist and book on edible fungi; it is the most common species in[87]Transylvania, tons of it sometimes appearing in the markets. Itdoes not possess that delicate flavour which is found in manyspecies, and although extolled by some beyond its merits, it isnevertheless perfectly wholesome, and, when young and carefullycooked, not to be despised. It must not be confoundedwith a very similar species (Agaricus euosmus, B.), with rosyspores, which is unpleasant.Agaricus tessellatus, Bull,Agaricuspometi, Fr.,Agaricus glandulosus, Bull, are all allies of the foregoing,and recorded as edible in the United States, although notone of the three has hitherto been recorded as occurring in GreatBritain. To these may also be added the following:—Agaricussalignus,[L] Fr., which is rare in England, but not uncommonabroad and in the United States. In Austria it is commonlyeaten.Agaricus ulmarius,[M] Bull, is common on elm trunks, notonly in Britain but also in North America, and is by somepreferred to the oyster mushroom. An allied species,Agaricusfossulatus, Cooke,[N] is found on the Cabul Hills, where it is collected,dried, and forms an article of commerce with the plains.Another, but smaller species, is dried in the air on strings passedthrough a hole in the short stem (Agaricus subocreatus, Cooke),and sent, it is believed, from China to Singapore.

The smallest species with which we have any acquaintance,that is edible, is the “nail fungus” (Agaricus esculentus,[O] Jacq.),scarcely exceeding one inch in diameter of the pileus, with athin rooting stem. The taste in British specimens when raw isbitter and unpleasant, but it is clearly eaten in Austria, as itsname testifies, and elsewhere in Europe. It is found in fir plantationsin the spring, at which season it is collected from the firwoods around and sent to Vienna, where it is only used forflavouring sauces under the name of “Nagelschwämme.”

Before quitting the group of true agarics, to which allhitherto enumerated belong, we must mention a few others ofless importance, but which are included amongst those good for[88]food. Foremost of these is a really splendid orange species(Agaricus cæsarius, Scop.[P]), which belongs to the same subgenusas the very deleterious fly-agaric, and the scarcely less fatalAgaricus vernus, Bull. It is universally eaten on the continent,but has hitherto never been found in Great Britain. In thesame subgenus,Agaricus strobiliformis,[Q] Fr., which is rare in thiscountry, and probably alsoAgaricus Ceciliæ, B. & Br.[R] Besidesthese,Agaricus excoriatus, Schæff.,Agaricus mastoideus, Fr.,Agaricus gracilentus, Kromb., andAgaricus holosericeus, Fr.,[S]all belonging to the same subgenus as the parasol mushroom,more or less uncommon in England.

Although the larger number of esculent agarics are white-spored,some few, worthy of note, will be found in the othersections, and notably amongst these the common mushroom andits congener the meadow, or horse mushroom. In addition tothose already enumerated, might be included also theAgaricuspudicus, Bull, which is certainly wholesome, as well as its ally,Agaricus leochromus, Cooke,[T] both of which have rusty spores.

The late Dr. Curtis,[U] in a letter to the Rev. M. J. Berkeley,enumerates several of the fungi which are edible amongst thosefound in the United States. Of these, he says,Agaricus amygdalinus,Curt., can scarcely be distinguished when cooked fromthe common mushroom.Agaricus frumentaceus, Bull, and threeallied new species, peculiar to the United States, are commended.Agaricus cæspitosus, Curt., he says, is found in enormous quantities,a single cluster containing from fifty to one hundred stems,and might well be deemed a valuable species in times of scarcity.It would not be highly esteemed where other and better speciescan be had, but it is generally preferred toAgaricus melleus, Fr.It is suitable for drying for winter use. In the same communication,he observes that the imperial (Agaricus cæsarius, Scop.),[89]grows in great quantities in oak forests, and may be obtainedby the cart-load in its season; but to his taste, and that of hisfamily, it is the most unpalatable of fungi, nor could he find anyof the most passionate mycophagists who would avow that theyliked it. There is a disagreeable saline flavour that they couldnot remove nor overlay. In addition to these, the same authorityenumeratesAgaricus russula, Schæff.,Agaricus hypopithyus,Curt., andAgaricus consociatus, Curt., the latter two being confinedto the United States;Agaricus columbetta, Fr., found inBritain, but not eaten, as well asAgaricus radicatus, Bull.Agaricusbombycinus, Schæff., andAgaricus speciosus, Fr., are found inBritain, but by no means common;Agaricus squarrosus, Mull.,has always been regarded with great suspicion in this country,where it is by no means uncommon;Agaricus cretaceus, Fr., andAgaricus sylvaticus, Schæff., are close allies of the commonmushroom.

Dr. Curtis says that hill and plain, mountain and valley,woods, fields, and pastures, swarm with a profusion of goodnutritious fungi, which are allowed to decay where they springup, because people do not know how, or are afraid, to use them.By those of us who know their use, their value was appreciated,as never before, during the late war, when other food, especiallymeat, was scarce and dear. Then such persons as I have heardexpress a preference for mushrooms over meat had generally noneed to lack grateful food, as it was easily had for the gathering,and within easy distance of their homes if living in the country.Such was not always the case, however. I remember once, duringthe gloomy period when there had been a protracted drought,and fleshy fungi were to be found only in damp shaded woods,and but few even there, I was unable to find enough of any onespecies for a meal, so, gathering of every kind, I brought homethirteen different kinds, had them all cooked together in onegrandpot pourri, and made an excellent supper.

One important use to which several species of fungi can beapplied, is the manufacture of ketchup. For this purpose, notonly is the mushroom,Agaricus campestris, and the horse mushroom,Agaricus arvensis, available, but alsoAgaricus rubescens[90]is declared to be excellent for the purpose, and a delicious, butpale, extract is to be obtained fromMarasmius oreades. Otherspecies, asCoprinus comatus, andCoprinus atramentarius, arealso available, together withFistulina hepatica, andMorchellaesculenta. In some districts, when mushrooms are scarce, it isstated that almost any species that will yield a dark juice iswithout scruple mixed with the common mushroom, and itshould seem without any bad consequence except the deteriorationof the ketchup.[V] There is an extensive manufacture ofketchup conducted at Lubbenham, near Market Harborough,but the great difficulty appears to be the prevention of decomposition.Messrs. Perkins receive tons of mushrooms fromevery part of the kingdom, and they find, even in the samespecies, an immense difference in the quality and quantity ofthe produce. The price of mushrooms varies greatly with theseason, ranging between one penny and sixpence per pound.Messrs. Perkins are very careful in their selection, but littlediscrimination is used by country manufacturers on a smallscale, who use such doubtful species asAgaricus lacrymabundus,withAgaricus spadiceus, and a host of allied species, which theycharacterize as nonpareils and champignons. In the easterncountiesAgaricus arvensis has the preference for ketchup.

The generic distinctions between the genuine Agarics andsome of the allied genera can hardly be appreciated by the non-botanicalreader, but we have nevertheless preferred groupingthe edible species together in a somewhat botanical order; and,pursuing this plan, the next species will be those ofCoprinus,in which the gills are deliquescent after the plant has arrivedat maturity. The maned mushroom (Coprinus comatus, Fr.)[W]is the best of edible species in this group. It is very commonhere by roadsides and other places, and whilst still young andcylindrical, and the gills still whitish or with a roseate tint, itis highly to be commended. Similar, but perhaps somewhatinferior, isCoprinus atramentarius, Fr.,[X] equally common about[91]old stumps and on the naked soil. Both species are also foundand eaten in the United States.

InCortinarius, the veil is composed of arachnoid threads, andthe spores are rusty. The number of edible species are few.Foremost is the really handsomeCortinarius violaeus, Fr.,[Y] oftennearly four inches in diameter, and of a beautiful violet colour;and the smallerCortinarius castaneus, Fr.,[Z] scarcely exceeding aninch in diameter, both being found in woods, and common aliketo Britain and the United States.Cortinarius cinnamomeus, Fr.,is also a lover of woods, and in northern latitudes is found inhabitingthem everywhere. It has a cinnamon-coloured pileus,with yellowish flesh, and its odour and flavour is said to partakeof the same spice. In Germany it is held in high esteem.Cortinariusemodensis, B., is eaten in Northern India.

The small genusLepista of Smith, (which, however, is notadopted by Fries in his now edition of the “Epicrisis”) includesone esculent species inLepista personata, theAgaricus personatusof Fries.[a] It is by no means uncommon in Northern Europeor America, frequently growing in large rings; the pileus ispallid, and the stem stained with lilac. Formerly it was saidto be sold in Covent Garden Market under the name of “blewits,”but we have failed to see or hear of it during many years inLondon.

Small fungi of ivory-whiteness are very common amongstgrass on lawns in autumn. These are chieflyHygrophorusvirgineus, Fr.,[b] and although not much exceeding an inch indiameter, with a short stem, and wide decurrent gills, they areso plentiful in season that quantity soon compensates for thesmall size. Except that it is occasionally eaten in France, itdoes not enjoy much reputation abroad. A larger species, varyingfrom buff to orange,Hygrophorus pratensis, Fr.,[c] is scarcelyless common in open pastures. This is very gregarious in habit,[92]often growing in tufts, or portions of rings. The pileus is fleshyin the centre, and the gills thick and decurrent. In France,Germany, Bohemia, and Denmark, it is included with esculentspecies. In addition may be mentionedHygrophorus eburneus,Fr., another white species, as alsoHygrophorus niveus, Fr., whichgrows in mossy pastures.Paxillus involutus, Fr.,[d] though verycommon in Europe, is not eaten, yet it is included by Dr. Curtiswith the esculent species of the United States.

The milky agarics, belonging to the genusLactarius, are distinguishedby the milky juice which is exuded when they arewounded. The spores are more or less globose, and rough orechinulate, at least in many species. The most notable esculentisLactarius deliciosus, Fr.,[e] in which the milk is at first saffron-red,and afterwards greenish, the plant assuming a lurid greenishhue wherever bruised or broken. Universal commendation seemsto fall upon this species, writers vying with each other to saythe best in its praise, and mycophagists everywhere endorsingthe assumption of its name, declaring it to be delicious. It isfound in the markets of Paris, Berlin, Prague, and Vienna, aswe are informed, and in Sweden, Denmark, Switzerland, Russia,Belgium; in fact, in nearly all countries in Europe it is esteemed.

Another esculent species,Lactarius volemum, Fr.,[f] has whitemilk, which is mild to the taste, whilst in deleterious specieswith white milk it is pungent and acrid. This species has beencelebrated from early times, and is said to resemble lamb’skidney.

Lactarius piperatus, Fr., is classed in England with dangerous,sometimes poisonous species, whereas the late Dr. Curtis, ofNorth Carolina, has distinctly informed us that it is cooked andeaten in the United States, and that he has partaken of it. HeincludesLactarius insulsus, Fr., andLactarius subdulcis, Fr.,[g]amongst esculent species; both are also found in this country,[93]but not reputed as edible; andLactarius angustissimus, Lasch,which is not British. Species ofLactarius seem to be eatenalmost indiscriminately in Russia when preserved in vinegar andsalt, in which condition they form an important item in thekinds of food allowed in their long fasts, someBoleti in thedried state entering into the same category.

The species ofRussula in many respects resembleLactariiwithout milk. Some of them are dangerous, and others esculent.Amongst the latter may be enumeratedRussula heterophylla,Fr., which is very common in woods. Vittadini pronounces itunsurpassed for fineness of flavour by even the notableAmanitacæsarea.[h] Roques gives also an account in its favour as consumedin France. Both these authors give favourable accountsofRussula virescens, P.,[i] which the peasants about Milan arein the habit of putting over wood embers to toast, and eatingafterwards with a little salt. Unfortunately it is by no meanscommon in England. A third species ofRussula, with buff-yellowgills, isRussula alutacea, Fr., which is by no means tobe despised, notwithstanding that Dr. Badham has placed itamongst species to be avoided. Three or four others have alsothe merit of being harmless, and these recorded as esculent bysome one or more mycological authors:Russula lactea, Fr., awhite species, found also in the United States;Russula lepida,Fr., a roseate species, found also in lower Carolina, U.S.; andanother reddish species,Russula vesca, Fr., as well asRussuladecolorans, Fr. Whilst writing of this genus, we may observe,by way of caution, that it includes also one very noxious redspecies,Russula emetica, Fr., with white gills, with which someof the foregoing might be confounded by inexperienced persons.

The chantarelleCantharellus cibarius, Fr., has a most charmingand enticing appearance and odour. In colour, it is of abright golden yellow, and its smell has been compared to that ofripe apricots. It is almost universally eaten in all countries[94]where it is found, England excepted, where it is only to bemet with at the “Freemason’s Tavern” on state occasions, andat the tables of pertinacious mycophagists.[j] Trattinnick says:“Not only this same fungus never did any one harm, but mighteven restore the dead.”[k]

The fairy-ring champignonMarasmius oreades, Fr., thoughsmall, is plentiful, and one of the most delicious of edible fungi.It grows in exposed pastures, forming rings, or parts of rings.This champignon possesses the advantage of drying readily,and preserving its aroma for a long time. We have oftenregretted that no persistent attempts and experiments havebeen made with the view of cultivating this excellent and usefulspecies.Marasmius scorodonius, Fr.,[l] a small, strong-scented,and in all respects inferior species, found on heaths and drypastures, extending even to the United States, is consumed inGermany, Austria, and other continental countries, where, perhapsits garlic odour has been one of its recommendations asan ingredient in sauces. In this enumeration we have not exhaustedall the gill-bearing species which might be eaten, havingincluded only those which have some reputation as esculents,and of these more particularly those found in Great Britain andthe United States.

Amongst thePolyporei, in which the gill plates are representedby pores or tubes, fewer esculent species are to be met with thanin theAgaricini, and the majority of these belong to the genusBoletus. Whilst in Vienna and Hanover, we were rathersurprised to findBoletus edulis, Fr., cut into thin slices anddried, exposed for sale in almost every shop where meal, peas,and other farinaceous edibles were sold. This species is commonenough in England, but as a rule it does not seem to pleasethe English palate, whereas on the continent no fungus is morecommonly eaten. This is believed to be the suillus eaten bythe ancient Romans,[m] who obtained it from Bithynia. The[95]modern Italians dry them on strings for winter use, and inHungary a soup is made from them when fresh. A moreexcellent species, according to our judgment, isBoletus æstivalis,Fr.,[n] which appears in early summer, and has a peculiar nuttyflavour when raw, reminding one more of a fresh mushroom.Boletus scaber, Fr.,[o] is also common in Britain, as well as thecontinent, but does not enjoy so good a reputation asB. edulis.Krombholz says thatBoletus bovinus, Fr., a gregarious species,found on heaths and in fir woods, is much sought after abroadas a dish, and is good when dried.Boletus castaneus, Fr.,[p] isa small species with a mild, pleasant taste when raw, and verygood when properly cooked. It is not uncommonly eaten onthe continent.Boletus chrysenteron, Fr.,[q] andBoletus subtomentosus,Fr., are said to be very poor eating, and some authorshave considered them injurious; but Mr. W. G. Smith statesthat he has on more than one occasion eaten the former, andTrattinnick states that the latter is eaten in Germany. The lateMr. Salter informed us that, when employed on the geologicalstaff, he at one time lived almost entirely on different species ofBoleti, without using much discrimination. Sir W. C. Trevelyanalso informs us that he has eatenBoletus luridus without anyunpleasant consequences, but we confess that we should be sorryto repeat the experiment. Dr. Badham remarks that he haseatenBoletus Grevillei, B.,Boletus flavus, With., andBoletusgranulatus, L., the latter being recognized also as edible abroad.Dr. Curtis experimented, in the United States, onBoletus collinitus,and although he professes not to be particularly fond ofthe Boleti, he recognizes it as esculent, and adds that it had beenpronounced delicious by some to whom he had sent it. He alsoenumerates as edibleBoletus luteus, Fr.,Boletus elegans, Fr.,Boletus flavidus, Fr.,Boletus versipellis, Fr.,Boletus leucomelas,Tr., andBoletus ovinus, Sch. Two Italian species ofPolyporusmust not be forgotten. These arePolyporus tuberaster, Pers.,[96]which is procured by watering thepietra funghaia, or fungusstone, a kind of tufa, in which the mycelium is embedded. Itis confined to Naples. The other species isPolyporus corylinus,Mauri., procured artificially in Rome from charred stumps of thecob-nut tree.[r]

Of truePolyporus, only two or three species have beenregarded favourably as esculents. These are—Polyporus intybaceus,Fr., which is of very large size, sometimes attaining asmuch as forty pounds;Polyporus giganteus, Fr., also very large,and leathery when old. Both these species are natives ofBritain. Only young and juicy specimens must be selected forcooking.Polyporus umbellatus, Fr., is stated by Fries to beesculent, but it is not found in Britain.Polyporus squamosus,Fr., has been also included; but Mrs. Hussey thinks that onemight as well think of eating saddle-flaps. None of thesereceive very much commendation. Dr. Curtis enumerates,amongst North American species, thePolyporus cristatus, Fr.,Polyporus poripes, Fr., which, when raw, tastes like the bestchestnuts or filberts, but is rather too dry when cooked.Polyporus Berkeleii, Fr., is intensely pungent when raw, butwhen young, and before the pores are visible, it may be eatenwith impunity, all its pungency being dissipated by cooking.Polyporus confluens, Fr., he considers superior, and, in fact,quite a favourite.Polyporus sulfureus, Fr., which is not eaten inEurope, he considers just tolerably safe, but not to be coveted.It is by no means to be recommended to persons with weakstomachs. In his catalogue, Dr. Curtis enumerates one hundredand eleven species of edible fungi found in Carolina.[s]

WithFistulina hepatica, Fr., it is different; for here weencounter a fleshy, juicy fungus, resembling beefsteak a little inappearance, and so much more in its uses, that the name of“beefsteak fungus” has been given to it. Some authors arerapturous in their praise ofFistulina. It sometimes attains avery large size, Dr. Badham quoting[t] one found by himself[97]nearly five feet in circumference, and weighing eight pounds;whilst another found by Mr. Graves weighed nearly thirtypounds. In Vienna it is sliced and eaten with salad, like beetroot,which it then much resembles. On the continent it iseverywhere included amongst the best of edible species.

TheHydnei, instead of pores or tubes, are characterized byspines or warts, over which the fructifying surface is expanded.The most common isHydnum repandum, Fr., found in woodsand woody places in England, and on the continent, extendinginto the United States. When raw, it is peppery to the taste,but when cooked is much esteemed. From its drier nature, itcan readily be dried for winter use. Less common in EnglandisHydnum imbricatum, Fr., although not so uncommon on thecontinent. It is eaten in Germany, Austria, Switzerland,France, and elsewhere.Hydnum lævigatum, Swartz, is eaten inAlpine districts.[u] Of the branched species,Hydnum coralloides,Scop.,[v] andHydnum Caput Medusæ, Bull,[w] are esculent, but veryrare in England. The latter is not uncommon in Austria andItaly, the former in Germany, Switzerland, and France.Hydnumerinaceum, Bull, is eaten in Germany[x] and France.

The Clavarioid fungi are mostly small, but of these the majorityof the white-spored are edible.Clavaria rugosa, Bull, is acommon British species, as also isClavaria coralloides, L., theformer being found also in the United States.Clavaria fastigiata,D. C., is not uncommon; butClavaria amethystina, Bull, abeautiful violet species, is rare. In France and Italy,Clavariacinerea, Bull, is classed with esculents; and it is not uncommonin Britain.Clavaria botrytis, P., andClavaria aurea, Schæff.,are large and beautiful species, but rare with us; they extendalso into the United States. Others might be named (Dr.Curtis enumerates thirteen species eaten in Carolina), which are[98]certainly wholesome, but they are of little importance as ediblespecies.Sparassis crispa, Fr., is, on the contrary, very large,resembling in size,[y] and somewhat in appearance, a cauliflower;it has of late years been found several times in this country.In Austria it is fricasseed with butter and herbs.

Of the true Tremellæ, none merit insertion here. The curiousJew’s ear (Hirneola auricula-Judæ, Fr.), with one or two otherspecies ofHirneola, are collected in great quantities in Tahiti,and shipped in a dried state to China, where they are used forsoup. Some of these find their way to Singapore.

The false truffles (Hypogæi) are of doubtful value, one species(Melanogaster variegatus, Tul.) having formerly been sold in themarkets of Bath as a substitute for the genuine truffle.[z] Neitheramongst thePhalloidei do we meet with species of any economicvalue. The gelatinous volva of a species ofIleodictyon is eatenby the New Zealanders, to whom it is known as thunder dirt;whilst that ofPhallus Mokusin is applied to a like purpose inChina;[AA] but these examples would not lead us to recommend asimilar use forPhallus impudicus, Fr., in Britain, or induce usto prove the assertion of a Scotch friend that the porous stem isvery good eating.

One species of puff-ball,Lycoperdon giganteum, Fr,[AB] hasmany staunch advocates, and whilst young and cream-like, it is,when well manipulated, an excellent addition to the breakfast-table.A decided advantage is possessed by this species, sinceone specimen is often found large enough to satisfy the appetitesof ten or twelve persons. Other species ofLycoperdon havebeen eaten when young, and we have been assured by thosewho have made the experiment, that they are scarcely inferiorto their larger congener.Bovista nigrescens, Fr., andBovistaplumbea, Fr., are also eaten in the United States. More thanone species ofLycoperdon andBovista appear in the bazaars ofIndia, as at Secunderabad and Rangoon; while the white ant-hills,[99]together with an excellent Agaric, produce one or morespecies ofPodaxon which are esculent when young. A speciesofScleroderma which grows abundantly in sandy districts, issubstituted for truffles in Perigord pies, of which, however, itdoes not possess any of the aroma.

Fig. 43.—Morchella gigaspora, from Kashmir.

Passing over the rest of the sporiferous fungi, we findamongst theAscomycetous group several that are highly esteemed.Amongst these may first be named the species of morel, whichare regarded as delicacies wherever they are found.Morchellaesculenta, Pers., is the most common species, but we have alsoMorchella semilibera, D. C., and the much largerMorchellacrassipes, Pers. Probably all the species ofMorchella areesculent, and we know that many besides the above are eatenin Europe and other places;Morchella deliciosa, Fr., in Java;Morchella bohemica, Kromb., in Bohemia;Morchella gigaspora,Cooke, andMorchella deliciosa, Fr., in Kashmere.[AC]Morchellarimosipes, D. C., occurs in France and Bohemia;Morchella[100]Caroliniana, Bosc., in the Southern United States of America.W. G. Smith records the occurrence in Britain of specimens ofMorchella crassipes, P., ten inches in height, and one specimenwas eleven inches high, with a diameter of seven and a halfinches.[AD]

Similar in uses, though differing in appearance, are the speciesofHelvella, of which several are edible. In both these genera,the individuals can be dried so readily that they are the morevaluable on that account, as they can be used for flavouring inwinter when fresh specimens of any kind of fungus are difficultto procure. The most common English species isHelvellacrispa, Fr., butHelvella lacunosa, Fr., is declared to beequally good, though not so large and somewhat rare.Helvellainfula, Fr., is also a large species, but is not British, although itextends to North America, as also doesHelvella sulcata, Afz.Intermediate between the morel andHelvella is the specieswhich was formerly included with the latter, but now known asGyromitra esculenta, Fr.[AE] It is rarely found in Great Britain,but is more common on the continent, where it is held in esteem.A curious stipitate fungus, with a pileus like a hood, calledVerpa digitaliformis, Pers.,[AF] is uncommon in England, butVittadini states that it is sold in the Italian markets, althoughonly to be recommended when no other esculent fungus offers,which is sometimes the case in spring.[AG]

Two or three species ofPeziza have the reputation of beingesculent, but they are of very little value; one of these isPezizaacetabulum, L., another isPeziza cochleata, Huds., and a thirdisPeziza venosa, Pers.[AH] The latter has the most decided nitrousodour, and also fungoid flavour, whilst the former seem to havebut little to recommend them; we have seen whole baskets fullofPeziza cochleata gathered in Northamptonshire as a substitutefor morels.

A very interesting genus of edible fungi, growing on evergreen[101]beech trees in South America, has been namedCyttaria.One of these,Cyttaria Darwinii, B., occurs in Terra del Fuego,where it was found by Mr. C. Darwin[AI] growing in vast numbers,and forming a very essential article of food for the natives.Another isCyttaria Berteroi, B., also seen by Mr. Darwin inChili, and eaten occasionally, but apparently not so good asthe preceding.[AJ] Another species isCyttaria Gunnii, B., whichabounds in Tasmania, and is held in repute amongst the settlersfor its esculent properties.[AK]

Fig. 44.—Cyttaria Gunnii, B.

It remains for us only to note the subterranean fungi, of whichthe truffle is the type, to complete our enumeration of esculentspecies. The truffle which is consumed in England isTuberæstivum, Vitt.; but in France the more highly-flavouredTubermelanospermum, Vitt.,[AL] and alsoTuber magnatum, Pico, withsome other species. In Italy they are very common, whilstsome are found in Algeria. One species at least is recorded inthe North-west of India, but in Northern Europe and NorthAmerica they appear to be rare, andTerfezia Leonis is used asan esculent in Damascus. A large species ofMylitta, sometimesseveral inches in diameter, occurs plentifully in some parts ofAustralia. Although often included with fungi, the curiousproduction known under the name ofPachyma cocos, Fr., is not[102]a fungus, as proved by the examinations made by the Rev. M. J.Berkeley. It is eaten under the name of “Tuckahoe” in theUnited States, and as it consists almost entirely of pectic acid,it is sometimes used in the manufacture of jelly.

In the Neilgherries (S. India), a substance is occasionallyfound which is allied to the native bread of southern latitudes.It is found at an elevation of 5,000 feet. The natives call it“a little man’s bread,” in allusion to the tradition that the Neilgherrieswere once peopled by a race of dwarfs.[AM] At first it wassupposed that these were the bulbs of some orchid, but lateranother view was held of their character. Mr. Scott, whoexamined the specimens sent down to him, remarks that, insteadof being the product of orchids, it is that of an undergroundfungus of the genusMylitta. It indeed seems, he says, veryclosely allied to, if really distinct from, the so-called nativebread of Tasmania.[AN]

Of the fungi employed in medicine, the first place must beassigned to ergot, which is the sclerotioid condition of a speciesofClaviceps. It occurs not only on rye but on wheat, and manyof the wild grasses. On account of its active principle, thisfungus still holds its place in the Materia Medica. Others whichformerly had a reputation are now discarded, as, for instance, thespecies ofElaphomyces; andPolyporus officinalis, Fr., which hasbeen partly superseded as a styptic by other substances, wasformerly employed as a purgative. The ripe spongy capillitiumof the great puff-ballLycoperdon giganteum, Fr., has been usedfor similar purposes, and also recommended as an anodyne;indeed formidable surgical operations have been performed underits influence, and it is frequently used as a narcotic in thetaking of honey. Langsdorf gives a curious account of itsemployment as a narcotic; and in a recent work on Kamtschatkait is said to obtain a very high price in that country.Dr. Porter Smith writes of its employment medicinally by theChinese, but from his own specimens it is clearly a species ofPolysaccum, which he has mistaken forLycoperdon. In China[103]several species are supposed to possess great virtue, notably theTorrubia sinensis, Tul.,[AO] which is developed on dead caterpillars;as it is, however, recommended to administer it as a stuffing toroast duck, we may be sceptical as to its own sanitary qualities.Geaster hygrometricus, Fr., we have also detected amongstChinese drugs, as also a species ofPolysaccum, and the smallhardMylitta lapidescens, Horn. In India, a large but imperfectfungus, named provisionallySclerotium stipitatum, Curr.,found in nests of the white ant, is supposed to possess greatmedicinal virtues.[AP] A species ofPolyporus (P. anthelminticus,B.), which grows at the root of old bamboos, is employed inBurmah as an anthelmintic.[AQ] In former times the Jew’s ear(Hirneola auricula Judæ, Fr.) was supposed to possess greatvirtues, which are now discredited. Yeast is still includedamongst pharmaceutical substances, but could doubtless be verywell dispensed with. Truffles are no longer regarded as aphrodisiacs.

For other uses, we can only allude to amadou, or Germantinder, which is prepared in Northern Europe fromPolyporusfomentarius, Fr., cut in slices, dried, and beaten until it is soft.This substance, besides being used as tinder, is made into warmcaps, chest protectors, and other articles. This same, or anallied species ofPolyporus, probablyP. igniarius, Fr., is driedand pounded as an ingredient in snuff by the Ostyacks onthe Obi. In Bohemia some of the large Polyporei, such asP. igniarius andP. fomentarius, have the pores and part of theinner substance removed, and then the pileus is fastened in aninverted position to the wall, by the part where originally itadhered to the wood. The cavity is then filled with mould,and the fungus is used, with good effect, instead of flower-pots,for the cultivation of such creeping plants as require but littlemoisture.[AR]

The barren mycelioid condition ofPenicillium crustaceum,[104]Fr., is employed in country districts for the domestic manufactureof vinegar from saccharine liquor, under the name ofthe “vinegar plant.” It is stated thatPolysaccum crassipes,D. C.,[AS] is employed in the South of Europe to produce a yellowdye; whilst recentlyPolyporus sulfureus, Fr., has been recommendedfor a similar purpose.Agaricus muscarius, Fr., the fly-agaric,known to be an active poison, is used in decoction insome parts of Europe for the destruction of flies and bugs.ProbablyHelotium æruginosum, Fr.,[AT] deserves mention here,because it stains the wood on which it grows, by means ofits diffuse mycelium, of a beautiful green tint, and the woodthus stained is employed for its colour in the manufacture ofTonbridge ware.

This completes the list, certainly of the most important, ofthe fungi which are of any direct use to humanity as food, medicine,or in the arts. As compared with lichens, the advantageis certainly in favour of fungi; and even when compared withalgæ, the balance appears in their favour. In fact, it may bequestioned whether, after all, fungi do not present a larger proportionof really useful species than any other of the cryptogams;and without any desire to disparage the elegance offerns, the delicacy of mosses, the brilliancy of some algæ, orthe interest which attaches to lichens, it may be claimed forfungi that in real utility (not uncombined with injuries as real)they stand at the head of the cryptogams, and in closestalliance with the flowering plants.

There are no phenomena associated with fungi that are ofgreater interest than those which relate to luminosity. Thefact that fungi under some conditions are luminous has longbeen known, since schoolboys in our juvenile days were in thehabit of secreting fragments of rotten wood penetrated bymycelium, in order to exhibit their luminous properties in thedark, and thus astonish their more ignorant or incredulous fellowsRumphius noted its appearance in Amboyna, and Fries,in his Observations, gives the name ofThelephora phosphoreato a species ofCorticium now known asCorticium cæruleum,on account of its phosphorescence under certain conditions.The same species is theAuricularia phosphorea of Sowerby,but he makes no note of its phosphorescence. Luminosity infungi “has been observed in various parts of the world, andwhere the species has been fully developed it has been generallya species ofAgaricus which has yielded the phenomenon.”[A]One of the best-known species is theAgaricus olearius of theSouth of Europe, which was examined by Tulasne with especialview to its luminosity.[B] In his introductory remarks, he saysthat four species only of Agaricus that are luminous appear atpresent to be known. One of them,A. olearius, D. C., is indigenousto Central Europe; another,A. igneus, Rumph., comesfrom Amboyna; the third,A. noctileucus, Lév., has been discovered[106]at Manilla by Gaudichaud, in 1836; the last,A. Gardneri,Berk., is produced in the Brazilian province of Goyaz, upondead leaves. As to theDematium violaceum, Pers., theHimantiacandida, Pers., cited once by Link, and theThelephora cærulea,D. C.(Corticium cæruleum, Fr.), Tulasne is of opinion that theirphosphorescent properties are still problematical; at least norecent observation confirms them.

The phosphorescence ofA. olearius, D. C., appears to havebeen first made known by De Candolle, but it seems that he wasin error in stating that these phosphorescent properties manifestthemselves only at the time of its decomposition. Fries,describing theCladosporium umbrinum, which lives upon theAgaric of the olive-tree, expressed the opinion that the Agariconly owes its phosphorescence to the presence of the mould.This, however, Tulasne denies, for he writes, “I have had theopportunity of observing that the Agaric of the olive is reallyphosphorescent of itself, and that it is not indebted to anyforeign production for the light it emits.” Like Delile, heconsiders that the fungus is only phosphorescent up to the timewhen it ceases to grow; thus the light which it projects, onemight say, is a manifestation of its vegetation.

“It is an important fact,” writes Tulasne, “which I can confirm,and which it is important to insist upon, that the phosphorescenceis not exclusively confined to the hymenial surface.Numerous observations made by me prove that the whole of thesubstance of the fungus participates very frequently, if notalways, in the faculty of shining in the dark. Among the firstAgarics which I examined, I found many, the stipe of whichshed here and there a light as brilliant as the hymenium, andled me to think that it was due to the spores which had fallenon the surface of the stipe. Therefore, being in the dark, Iscraped with my scalpel the luminous parts of the stipe, but itdid not sensibly diminish their brightness; then I split the stipe,bruised it, divided it into small fragments, and I found thatthe whole of this mass, even in its deepest parts, enjoyed, in asimilar degree to its superficies, the property of light. I found,besides, a phosphorescence quite as brilliant in all the cap, for,[107]having split it vertically in the form of plates, I found that thetrama, when bruised, threw out a light equal to that of theirfructiferous surfaces, and there is really only the superiorsurface of the pileus, or its cuticle, which I have never seenluminous.

“As I have said, the Agaric of the olive-tree, which is itselfvery yellow, reflects a strong brilliant light, and remainsendowed with this remarkable faculty whilst it grows, or, atleast, while it appears to preserve an active life, and remainsfresh. The phosphorescence is at first, and more ordinarily, recognizableat the surface of the hymenium. I have seen a greatnumber of young fungi which were very phosphorescent in thegills, but not in any other part. In another case, and amongstmore aged fungi, the hymenium of which had ceased to givelight, the stipe, on the contrary, threw out a brilliant glare.Habitually, the phosphorescence is distributed in an unequalmanner upon the stipe, and the same upon the gills. Althoughthe stipe is luminous at its surface, it is not always necessarilyso in its interior substance, if one bruises it, but this substancefrequently becomes phosphorescent after contact with the air.Thus, I had irregularly split and slit a large stipe in its length,and I found the whole flesh obscure, whilst on the exterior weresome luminous places. I roughly joined the lacerated parts,and the following evening, on observing them anew, I foundthem all flashing a bright light. At another time, I had witha scalpel split vertically many fungi in order to hasten theirdessication; the evening of the same day, the surface of all thesecuts was phosphorescent, but in many of these pieces of fungithe luminosity was limited to the cut surface which remainedexposed to the air; the flesh beneath was unchanged.

“I have seen a stipe opened and lacerated irregularly, thewhole of the flesh of which remained phosphorescent duringthree consecutive evenings, but the brightness diminished inintensity from the exterior to the interior, so that on the thirdday it did not issue from the inner part of the stipe. Thephosphorescence of the gills is in no way modified at first byimmersing the fungus in water; when they have been immersed[108]they are as bright as in the air, but the fungi which I leftimmersed until the next evening lost all their phosphorescence,and communicated to the water an already sensible yellow tint;alcohol put upon the phosphorescent gills did not at once completelyobliterate the light, but visibly enfeebled it. As to thespores, which are white, I have found many times very densecoats of them thrown down on porcelain plates, but I havenever seen them phosphorescent.

“As to the observation made by Delile that the Agaric of theolive does not shine during the day when placed in total darkness,I think that it could not have been repeated. From whatI have said of the phosphorescence ofA. olearius, one naturallyconcludes that there does not exist any necessary relationbetween this phenomenon and the fructification of the fungus;the luminous brightness of the hymenium shows, says Delile,‘the greater activity of the reproductive organs,’ but it isnot in consequence of its reproductive functions, which maybe judged only as an accessory phenomenon, the cause of whichis independent of, and more general than these functions, sinceall the parts of the fungus, its entire substance, throws forthat one time, or at successive times, light. From these experimentsTulasne infers that the same agents, oxygen, water, andwarmth, are perfectly necessary to the production of phosphorescenceas much in living organized beings as in those whichhave ceased to live. In either case, the luminous phenomenaaccompany a chemical reaction which consists principally ina combination of the organized matter with the oxygen of theair; that is to say, in its combustion, and in the dischargeof carbonic acid which thus shows itself.”

We have quoted at considerable length from these observationsof Tulasne on the Agaric of the olive, as they serve verymuch to illustrate similar manifestations in other species, whichdoubtless resemble each other in their main features.

Mr. Gardner has graphically described his first acquaintancein Brazil with the phosphorescent species which now bears hisname. It was encountered on a dark night of December, whilepassing through the streets of Villa de Natividate. Some boys[109]were amusing themselves with some luminous object, which atfirst he supposed to be a kind of large fire-fly, but on makinginquiry he found it to be a beautiful phosphorescent Agaric,which he was told grew abundantly in the neighbourhood onthe decaying fronds of a dwarf palm. The whole plant givesout at night a bright light somewhat similar to that emittedby the larger fire-flies, having a pale greenish hue. From thiscircumstance, and from growing on a palm, it was called by theinhabitants “flor de coco.”[C]

The number of recognized phosphorescent species ofAgaricusis not large, although two or three others may be enumeratedin addition to those cited by Tulasne. Of these,Agaricuslampas, and some others, are found in Australia.[D] In additionto theAgaricus noctileucus, discovered by Gaudichaud, and theAgaricus igneus of Rumphius, found in Amboyna, Dr. Hookerspeaks of the phenomenon as common in Sikkim, but he seemsnever to have been able to ascertain with what species it wasassociated.

Dr. Cuthbert Collingwood has communicated some furtherinformation relative to the luminosity of a species ofAgaricusin Borneo (supposed to beA. Gardneri), in which he says,“The night being dark, the fungi could be very distinctly seen,though not at any great distance, shining with a soft palegreenish light. Here and there spots of much more intenselight were visible, and these proved to be very young andminute specimens. The older specimens may more properlybe described as possessing a greenish luminous glow, like theglow of the electric discharge, which, however, was quite sufficientto define its shape, and, when closely examined, the chiefdetails of its form and appearance. The luminosity did notimpart itself to the hand, and did not appear to be affected bythe separation from the root on which it grew, at least not forsome hours. I think it probable that the mycelium of thisfungus is also luminous, for, upon turning up the ground insearch of small luminous worms, minute spots of light were[110]observed, which could not be referred to any particular objector body when brought to the light and examined, and wereprobably due to some minute portions of its mycelium.”[E] Thesame writer also adds, “Mr. Hugh Low has assured me that hesaw the jungle all in a blaze of light (by which he could see toread) as, some years ago, he was riding across the island bythe jungle road; and that this luminosity was produced by anAgaric.”

Similar experiences were detailed by Mr. James Drummondin a letter from Swan River, in which two species of Agaricare concerned. They grew on the stumps of trees, and hadnothing remarkable in their appearance by day, but by nightemitted a most curious light, such as the writer never sawdescribed in any book. One species was found growing on thestump of aBanksia in Western Australia. The stump was atthe time surrounded by water. It was on a dark night, whenpassing, that the curious light was first observed. When thefungus was laid on a newspaper, it emitted by night a phosphorescentlight, enabling persons to read the words around it, andit continued to do so for several nights with gradually decreasingintensity as the plant dried up. In the other instance,which occurred some years after, the author, during one of hisbotanical trips, was struck by the appearance of a large Agaric,measuring sixteen inches in diameter, and weighing about fivepounds. This specimen was hung up to dry in the sitting-room,and on passing through the apartment in the dark it wasobserved to give out the same remarkable light. The luminousproperty continued, though gradually diminishing, for four orfive nights, when it ceased on the plant becoming dry. “Wecalled some of the natives,” he adds, “and showed them thisfungus when emitting light, and the poor creatures cried out‘chinga,’ their name for a spirit, and seemed much afraidof it.”[F]

Although the examples already cited are those of species ofAgaric, luminosity is not by any means wholly confined to that[111]genus. Mr. Worthington Smith has recorded his experiences ofsome specimens of the commonPolyporus annosus which werefound on some timbers in the Cardiff coal mines. He remarksthat the colliers are well acquainted with phosphorescent fungi,and the men state that sufficient light is given “to see theirhands by.” The specimens ofPolyporus were so luminousthat they could be seen in the dark at a distance of twentyyards. He observes further, that he has met with specimens ofPolyporus sulfureus which were phosphorescent. Some of thefungi found in mines, which emit light familiar to the miners,belong to the incomplete genusRhizomorpha, of which Humboldtamongst others gives a glowing account. Tulasne has alsoinvestigated this phenomenon in connection with the commonRhizomorpha subterranea, Pers. This species extends underneaththe soil in long strings, in the neighbourhood of old tree stumps,those of the oak especially, which are becoming rotten, andupon these it is fixed by one of its branches. These are cylindrical,very flexible, branching, and clothed with a hard bark,encrusting and fragile, at first smooth and brown, becominglater very rough and black. The interior tissue, at first whitish,afterwards of a more or less deep brown colour, is formed ofextremely long parallel filaments from .0035 to .015mm. indiameter.

On the evening of the day when I received the specimens,[G]he writes, the temperature being about 22° Cent., all the youngbranches brightened with an uniform phosphoric light the wholeof their length; it was the same with the surface of some of theolder branches, the greater number of which were still brilliant insome parts, and only on their surface. I split and lacerated manyof these twigs, but their internal substance remained dull. Thenext evening, on the contrary, this substance, having been exposedto contact with the air, exhibited at its surface the samebrightness as the bark of the branches. I made this observationupon the old stalks as well as upon the young ones. Prolongedfriction of the luminous surfaces reduced the brightness[112]and dried them to a certain degree, but did not leave on thefingers any phosphorescent matter. These parts continued withthe same luminous intensity after holding them in the mouth soas to moisten them with saliva; plunged into water, held to theflame of a candle so that the heat they acquired was very appreciableto the touch, they still emitted in the dark a feeble light; itwas the same after being held in water heated to 30° C.; but puttingthem in water bearing a temperature of 55° C. extinguishedthem entirely. They are equally extinguished if held in the mouthuntil they catch the temperature; perhaps, still, it might beattributed less to the heat which is communicated to them thanto the deficiency of sufficient oxygen, because I have seen somestalks, having become dull in the mouth, recover after a fewinstants a little of their phosphorescence. A young stalkwhich had been split lengthwise, and the internal substance ofwhich was very phosphorescent, could imbibe olive oil manytimes and yet continue for a long time to give a feeble light.By preserving theseRhizomorphæ in an adequate state ofhumidity, I have been able for many evenings to renew theexamination of their phosphorescence; the commencement ofdessication, long before they really perish, deprives them of thefaculty of giving light. Those which had been dried for morethan a month, when plunged into water, commenced to vegetateanew and send forth numerous branches in a few days; but Icould only discover phosphorescence at the surface of these newformations, or very rarely in their immediate neighbourhood,the mother stalks appearing to have lost by dessication theirluminous properties, and did not recover them on being recalledto life. These observations prove that what Schmitz has writtenwas not true, that all parts of these fungi were seldom phosphorescent.

The luminous phenomenon in question is without doubt morecomplicated than it appears, and the causes to which we attributeit are certainly powerfully modified by the general characterof the objects in which they reside. Most of the Germanbotanists give this explanation, others suppose that it forms atfirst or during its continuance a special matter, in which the[113]luminous property resides; this matter, which is said to bemucilaginous in the luminous wood, appears to be in theRhizomorpha only a kind of chemical combination between themembrane and some gummy substance which they contain.Notwithstanding this opinion, I am assured that all externalmucous matter was completely absent from theAgaricus olearius,and I neither discovered it upon the branches ofRhizomorphasubterranea nor upon the dead leaves which I have seen phosphorescent;in all these objects the luminous surfaces werenothing else than their proper tissue.

It may be remarked here that the so-called species ofRhizomorphaare imperfect fungi, being entirely devoid of fructification,consisting in fact only of a vegetative system—a sort ofcompact mycelium—(probably of species ofXylaria) with someaffinity toSclerotium.

Recently an extraordinary instance of luminosity was recordedas occurring in our own country.[H] “A quantity of wood hadbeen purchased in a neighbouring parish, which was dragged upa very steep hill to its destination. Amongst them was a log oflarch or spruce, it is not quite certain which, 24 feet long and afoot in diameter. Some young friends happened to pass up thehill at night, and were surprised to find the road scattered withluminous patches, which, when more closely examined, proved tobe portions of bark or little fragments of wood. Following thetrack, they came to a blaze of white light which was perfectlysurprising. On examination, it appeared that the whole of theinside of the bark of the log was covered with a white byssoidmycelium of a peculiarly strong smell, but unfortunately in sucha state that the perfect form could not be ascertained. This wasluminous, but the light was by no means so bright as in thoseparts of the wood where the spawn had penetrated more deeply,and where it was so intense that the roughest treatment scarcelyseemed to check it. If any attempt was made to rub off theluminous matter it only shone the more brightly, and when wrappedup in five folds of paper the light penetrated through all the foldson either side as brightly as if the specimen was exposed; when,[114]again, the specimens were placed in the pocket, the pocket whenopened was a mass of light. The luminosity had now beengoing on for three days. Unfortunately we did not see it ourselvestill the third day, when it had, possibly from a change inthe state of electricity, been somewhat impaired; but it wasstill most interesting, and we have merely recorded what weobserved ourselves. It was almost possible to read the time onthe face of a watch even in its less luminous condition. We donot for a moment suppose that the mycelium is essentiallyluminous, but are rather inclined to believe that a peculiar concurrenceof climatic conditions is necessary for the productionof the phenomenon, which is certainly one of great rarity.Observers as we have been of fungi in their native haunts forfifty years, it has never fallen to our lot to witness a similar casebefore, though Prof. Churchill Babington once sent us specimensof luminous wood, which had, however, lost their luminositybefore they arrived. It should be observed that the parts of thewood which were most luminous were not only deeply penetratedby the more delicate parts of the mycelium, but were thosewhich were most decomposed. It is probable, therefore, thatthis fact is an element in the case as well as the presence offungoid matter.”

In all cases of phosphorescence recorded, the light emittedis described as of the same character, varying only in intensity.It answers well to the name applied to it, as it seems remarkablysimilar to the light emitted by some living insects and otheranimal organisms, as well as to that evolved, under favourableconditions, by dead animal matter—a pale bluish light, resemblingthat emitted by phosphorus as seen in a dark room.

Another phenomenon worthy of note is the change of colourwhich the bruised or cut surface of some fungi undergo. Mostprominent amongst these are certain poisonous species ofBoletus, such, for instance, asBoletus luridus, and someothers, which, on being bruised, cut, or divided, exhibit anintense, and in some cases vivid, blue. At times this changeis so instantaneous that before the two freshly-cut portionsof aBoletus can be separated, it has already commenced, and[115]proceeds rapidly till the depth of intensity has been gained.This blue colour is so universally confined to dangerous speciesthat it is given as a caution that all species which exhibit a bluecolour when cut or bruised, should on no account be eaten. Thedegree of intensity varies considerably according to the conditionof the species. For example,Boletus cærulescens issometimes only very slightly, if at all, tinged with blue whencut, though, as the name implies, the peculiar phenomenon isgenerally highly developed. It cannot be said that this changeof colour has as yet been fully investigated. One writer sometime since suggested, if he did not affirm, that the colour wasdue to the presence of aniline, others have contented themselveswith the affirmation that it was a rapid oxidization and chemicalchange, consequent upon exposure of the surfaces to the air.Archdeacon Robinson examined this phenomenon in differentgases, and arrived at the conclusion that the change depends onan alteration of molecular arrangement.[I]

One of the best of the edible species ofLactarius, known asLactarius deliciosus, changes, wherever cut or bruised, to a dulllivid green. This fungus is filled with an orange milky fluid,which becomes green on exposure to the air, and it is consequentlythe juice which oxidizes on exposure. Some varietiesmore than others of the cultivated mushroom become brownishon being cut, and a similar change we have observed, thoughnot recorded, in other species.

The presence of a milky juice in certain fungi has beenalluded to. This is by no means confined to the genusLactarius,in which such juice is universal, sometimes white, sometimesyellow, and sometimes colourless. In Agarics, especiallyin the subgenusMycena, the gills and stem are replete with amilky juice. Also in some species ofPeziza, as for instance inPeziza succosa, B., sometimes found growing on the ground ingardens, and inPeziza saniosa, Schrad., also a terrestrial species,the same phenomenon occurs. To this might be added suchspecies asStereum spadiceum, Fr., andStereum sanguinolentum,[116]Fr., both of which become discoloured and bleeding whenbruised, whileCorticium lactescens distils a watery milk.

Fungi in general have not a good repute for pleasant odours,and yet it must be conceded that they are not by any means devoidof odour, sometimes peculiar, often strong, and occasionallyvery offensive. There is a peculiar odour common to a greatmany forms, which has come to be called a fungoid odour; it isthe faint smell of a long-closed damp cellar, an odour of mouldinessand decay, which often arises from a process of eremocausis.But there are other, stronger, and equally distinct odours,which, when once inhaled, are never to be forgotten. Amongstthese is the fetid odour of the common stinkhorn, which is intensifiedin the more beautiful and curiousClathrus. It is veryprobable that, after all, the odour of thePhallus would not be sounpleasant if it were not so strong. It is not difficult to imagine,when one encounters a slight sniff borne on a passing breeze,that there is the element of something not by any means unpleasantabout the odour when so diluted; yet it must be confessedthat when carried in a vasculum, in a close carriage, orrailway car, or exposed in a close room, there is no scruple aboutpronouncing the odour intensely fetid. The experience of morethan one artist, who has attempted the delineation ofClathrusfrom the life, is to the effect that the odour is unbearable evenby an enthusiastic artist determined on making a sketch.

Perhaps one of the most fetid of fungi isThelephora palmata.Some specimens were on one occasion taken by Mr. Berkeley intohis bedroom at Aboyne, when, after an hour or two, he was horrifiedat finding the scent far worse than that of any dissectingroom. He was anxious to save the specimens, but the scent wasso powerful that it was quite intolerable till he had wrapped themin twelve thick folds of the strongest brown paper. The scentofThelephora fastidiosa is bad enough, but, like that ofCoprinuspicaceus, it is probably derived from the imbibition of the ordureon which it is developed. There needs no stronger evidencethat the scent must not only be powerful, but unpleasant, whenan artist is compelled, before a rough sketch is more than halffinished, to throw it away, and seek relief in the open air. A great[117]number of edible Agarics have the peculiar odour of fresh meal,but two species,Agaricus odorus andAgaricus fragrans, have apleasant anise-like odour. In two or three species of toughHydnum, there is a strong persistent odour somewhat like melilotor woodruffe, which does not pass away after the specimen hasbeen dried for years. In some species ofMarasmius, there is adecidedly strong odour of garlic, and in one species ofHygrophorus,such a resemblance to that of the larva of the goatmoth, that it bears the name ofHygrophorus cossus. Most ofthe fleshy forms exhale a strong nitrous odour during decay,but the most powerful we remember to have experienced wasdeveloped by a very large specimen ofChoiromyces meandriformis,a gigantic subterranean species of the truffle kind, and thisspecimen was four inches in diameter when found, and thenpartially decayed. It was a most peculiar, but strong andunpleasantly pungent nitrous odour, such as we never rememberto have met with in any other substance.Peziza venosa isremarkable when fresh for a strong scent like that ofaquafortis.

Of colour, fungi exhibit an almost endless variety, from white,through ochraceous, to all tints of brown until nearly black, orthrough sulphury yellow to reds of all shades, deepening intocrimson, or passing by vinous tints into purplish black. Theseare the predominating gradations, but there are occasional bluesand mineral greens, passing into olive, but no pure or chlorophyllousgreen. The nearest approach to the latter is found inthe hymenium of someBoleti. Some of the Agarics exhibitbright colours, but the larger number of bright-coloured speciesoccur in the genusPeziza. Nothing can be more elegant thanthe orange cups ofPeziza aurantia, the glowing crimson ofPeziza coccinea, the bright scarlet ofPeziza rutilans, the snowywhiteness ofPeziza nivea, the delicate yellow ofPeziza theleboloides,or the velvety brown ofPeziza repanda. AmongstAgarics, the most nobleAgaricus muscarius, with its wartycrimson pileus, is scarcely eclipsed by the continental orangeAgaricus cæsarius. The amethystine variety ofAgaricus laccatusis so common and yet so attractive; whilst some forms and[118]speciesRussula are gems of brilliant colouring. The goldentufts of more than one species ofClavaria are exceedinglyattractive, and the delicate pink of immatureLycogala epidendrumis sure to command admiration. The minute formswhich require the microscope, as much to exhibit their colouras their structure, are not wanting in rich and delicate tints,so that the colour-student would find much to charm him, andgood practice for his pencil in these much despised examples oflow life.

Amongst phenomena might be cursorily mentioned thepeculiar sarcodioid mycelium ofMyxogastres, the developmentof amœboid forms from their spores, and the extraordinaryrapidity of growth, as the well-known instance of theReticulariawhich Schweinitz observed running over iron a few hours afterit had been red hot. Mr. Berkeley has observed that the creamymycelium ofLycogala will not revive after it has become dryfor a few hours, though so active before.

A work of this character would hardly be deemed completewithout some reference to the above subject, which has moreovera relation to some of the questions discussed, and particularly ofspore diffusion in the atmosphere. The largest spore is microscopic,and the smallest known scarcely visible under a magnifyingpower of 360 diameters. Taking into account the largenumber of species of fungi, probably scarcely less numerous thanall the flowering plants, and the immense number of spores whichsome of the individuals produce, they must be exceedingly plentifuland widely diffused, though from their minuteness not easyto be discerned. It has been attempted to estimate the numberof spores which might be produced by one single plant ofLycoperdon,but the number so far exceeds that which the mind isaccustomed to contemplate that it seems scarcely possible torealize their profusion. Recent microscopic examinations of thecommon atmosphere[A] show the large quantity of spores that arecontinually suspended. In these investigations it was found thatspores and similar cells were of constant occurrence, and weregenerally present in considerable numbers. That the majorityof the cells were living, and ready to undergo development onmeeting with suitable conditions, was very manifest, as in thosecases in which preparations were retained under observation forany length of time, germination rapidly took place in many ofthe cells. In few instances did any development take place,[120]beyond the formation of networks of mycelium, or masses oftoruloid cells, but, in one or two, distinct sporules were developedon the filaments arising from some of the larger septate spores;and in a few others,Penicillium andAspergillus produced theircharacteristic heads of fructification. With regard to the precisenature of the spores, and other cells present in various instances,little can be said, as, unless their development were to be carefullyfollowed out through all its stages, it is impossible to referthem to their correct species or even genera. The greaternumber of them are apparently referable to the old orders offungi,Sphæronemei,Melanconei,Torulacei,Dematiei andMucedines,while some probably belonged to thePucciniæi andCæomacei.

Hence it is demonstrated that a large number of the sporesof fungi are constantly present in the atmosphere, which is confirmedby the fact that whenever a suitable pabulum is exposedit is taken possession of by floating spores, and soon convertedinto a forest of fungoid vegetation. It is admitted that thespores of such common moulds asAspergillus andPenicilliumare so widely diffused, that it is almost impossible to excludethem from closed vessels, or the most carefully guarded preparations.Special contrivances for the dispersion of the spores inthe different groups follow a few general types, and it is onlyrarely that we meet with any method that is confined only to aspecies or genus. Some of the more significant forms of sporesmay be illustrated, with their modes of dissemination.

Basidiospores is a term which we may employ here to designateall spores borne at the tips of such supports as are foundin theHymenomycetes andGasteromycetes, to which the nameof basidia has been given. In fact, under this section we mayinclude all the spores of those two orders, although we may beignorant of the precise mode in which the fruit of most of theMyxogastres is developed. Guarding ourselves at the outsetagainst any misinterpretation as to the use of this term, which,in fact, we employ simply to designate the fruit ofHymenomycetes,we may have excuse in our desire to limit special terms asmuch as possible. In theAgaricini the spores are plentiful, and[121]are distributed over the hymenium or gill plates, the surface ofwhich is studded with basidia, each of which normally terminateswith four short, erect, delicate, thread-like processes,each of which is surmounted by a spore. These spores arecolourless or coloured, and it is upon this fact that primary divisionsin the genusAgaricus are based, inasmuch as colour in thespores appears to be a permanent feature. In white-spored speciesthe spores are white in all the individuals, not mutable as thecolour of the pileus, or the corolla in phanerogamic plants. Soalso with the pink spored, rusty spored, black spored, and others.This may serve to explain why colour, which is so little reliedupon in classification amongst the higher plants, should be introducedas an element of classification in one of the largestgenera of fungi.

Fig. 45.—Spores of (a)Agaricus mucidus; (b)Agaricus vaginatus; (c)Agaricus pascuus; (d)Agaricus nidorosus; (e)Agaricus campestris. (Smith.)

Fig. 46.—Spores of (a)Lactarius blennius; (b)Lactarius fuliginosus; (c)Lactarius quietus. (Smith.)

There are considerable differences in size and form amongstthe spores of theAgaricini, although at first globose; whenmature they are globose, oval, oblong, elliptic, fusiform, andeither smooth or tuberculated, often maintaining in the differentgenera or subgenera one particular characteristic, or typicalform. It is unnecessary here to particularize all the modifications[122]which the form and colour of the spores undergo in differentspecies, as this has already been alluded to. The sporesin thePolyporei,Hydnei, &c., are less variable, of a similarcharacter, as in all theHymenomycetes, except perhaps theTremellini.

Fig. 46a.—(a) Spore ofGomphidius viscidus; (b) spore ofCoprinus micaceus.

Fig. 47.—Spores of (a)Polyporus cæsius; (b)Boletus parasiticus; (c)Hydnum.

When an Agaric is mature, if the stem is cut off close to thegills, and the pileus inverted, with the gills downwards on asheet of black paper (one of the pale-spored species is best forthis purpose), and left for a few hours, or all night, in thatposition, the paper will be found imprinted in the morningwith a likeness of the under side of the pileus with its radiatinggills, the spores having been thrown down upon the paper insuch profusion, from the hymenium, and in greater numbersfrom the opposed surfaces of the gills. This little experimentwill be instructive in two or three points. It will illustrate thefacility with which the spores are disseminated, the immensenumber in which they are produced, and the adaptability of thegill structure to the economy of space, and the development ofthe largest number of basidiospores from a given surface. Thetubes or pores inPolyporei, the spines inHydnei, are modificationsof the same principles, producing a like result.

In theGasteromycetes the spores are produced in many cases,probably in most, if not all, at the tips of sporophores; but thehymenium, instead of being exposed, as in theHymenomycetes, isenclosed within an outer peridium or sac, which is sometimesdouble. The majority of these spores are globose in form, someof them extremely minute, variously coloured, often dark, nearlyblack, and either externally smooth or echinulate. In somegenera, asEnerthenema,Badhamia, &c., a definite number ofspores are at first enclosed in delicate cysts, but these are exceptions[123]to the general rule: this also is the case in at least onespecies ofHymenogaster. As the spores approach maturity, itmay be observed in such genera asStemonitis,Arcyria,Diachea,Dictydium,Cribraria,Trichia, &c., that they are accompanied bya sort of reticulated skeleton of threads, which remainpermanent, and served in earlier stages, doubtless,as supports for the spores; being, in fact, theskeleton of the hymenium. It has been suggestedthat the spiral character of the threads inTrichiacalls to mind the elaters in theHepaticæ, and likethem may, by elasticity, aid in the dispersion of thespores. There is nothing known, however, whichwill warrant this view. When the spores aremature, the peridium ruptures either by an externalorifice, as inGeaster,Lycoperdon, &c., or by anirregular opening, and the light, minute, delicate,spores are disseminated by the slightest breath ofair. Specimens ofGeaster andBovista are easilyseparated from the spot on which they grew; whenrolling from place to place, the spores are depositedover a large surface. In thePhalloidei the sporesare involved in a slimy mucus which would prevent their diffusionin such a manner. This gelatinous substance has neverthelessa peculiar attraction for insects, and it is not altogetherromantic to believe that in sucking up the fetid slime, theyalso imbibe the spores and transfer them from place to place,so that even amongst fungi insects aid in the dissemination ofspecies. Whether or not theMyxogastres should be includedhere is matter of opinion, since the mode in which the sporesare developed is but little known; analogy with theTrichogastresin other points alone leading to the conclusion that they mayproduce basidiospores. The slender, elastic stems which supportthe peridia in many species are undoubted aids to thedissemination of the spores.[B]

Fig. 48.—Diachea elegans.

Under the name ofStylospores may be classed those sporeswhich in some orders ofConiomycetes are produced at the apex[124]of short threads, either enclosed in a perithecium, or seated upona kind of stroma. These are exceedingly variable, sometimeslarge, and multiseptate, at other times minute, resembling spermatia.In such genera as are chiefly epiphytal, inSeptoria,Phyllosticta, and their allies, the minute spores are enclosedwithin membranaceous perithecia, and when mature these areejected from the orifice at the apex, or are exposed by the breakingoff of the upper portion of the perithecia. InDiplodia andHendersonia the spores are larger, mostly coloured, often veryfine in the latter genus,and multiseptate, escapingfrom the perithecia by aterminal pore. Probablythe species are only pycnidiaofSphæriacei, butthat is of no consequencein relation to our presentinquiry. Of stylosporeswhich deserve mention onaccount of their singularityof form, we maynote those ofDilophospora graminis, which are straight, andhave two or three hair-like appendages at each extremity. InDiscosia there is a single oblique bristle at each end, or atthe side of the septate spores, whilst inNeottiospora a tuft ofdelicate hairs is found at one extremity only. The appendagesinDinemasporium are similar to those ofDiscosia. The spores[125]inProsthemium may be said in some sort to resemble compoundHendersonia, being fusiform and multiseptate, often united atthe base in a stellate manner. In this genus, as inDarluca,Cytispora, and the most of those belonging to theMelanconiei,the spores when mature are expelled from the orifice of theperithecium or spurious perithecium, either in the form oftendrils, or in a pasty mass. In these instances the spores aremore or less involved in gelatine, and when expelled lie spreadover the matrix, around the orifice; their ultimate diffusionbeing due to moisture washing them over other parts of thesame tree, since it is probable that their natural area ofdissemination is not large, the higher plants, of which theyare mostly conditions, being developed on the same branches.More must be known of the relations betweenMelanconiumand Tulasne’s sphæriaceous genusMelanconis before we canappreciate entirely the advantage toMelanconium and someother genera, that the wide diffusion of their spores should bechecked by involving them in mucus, or their being agglutinatedto the surface of the matrix, only to be softened and diffused byrain. The spores in many species amongst theMelanconiei areremarkably fine; those ofStegonosporium have the endochromepartite and cellular. InStilbospora andCoryneum the spores aremultiseptate, large, and mostly coloured. InAsterosporium the[126]spores are stellate, whilst inPestalozzia they are septate, with apermanent peduncle, and crested above with two or three hyalineappendages.

Fig. 49.—Spore ofHendersonia polycystis.	Fig. 50.—Spores ofDilophospora graminis.
Fig. 51.—Spores ofDiscosia.	Fig. 52.—Spore ofProsthemium betulinum.
Fig. 53.—Spore ofStegonosporium cellulosum.	Fig. 54.—Stylospores ofCoryneum disciforme.
Fig. 55.—Spores ofAsterosporium Hoffmanni.	Fig. 56.—Spores ofPestalozzia.
Fig. 57.—Bispora monilioides.

TheTorulacei externally, and to the naked eye, are verysimilar to the black moulds, and the mode of dissemination willbe alike in both. The spores are chiefly compound, at firstresembling septate threads, and at length breaking up intojoints, each joint of which possesses the function of a spore. Insome instances the threads are connate, side by side, as inTorulahysterioides, and inSpeira, being concentrically arranged inlaminæ in the latter genus. The structure inSporochisma isvery peculiar, the joints breaking up within an external tube ormembrane. The spores inSporidesmium appear to consist ofirregular masses of cells, agglomerated into a kind of compoundspore. Most of the species become pulverulent, and the sporesare easily diffused through the air like an impalpable dust.They form a sort of link between the stylospores of one sectionof theConiomycetes, and the pseudospores of the parasiticalsection.

Pseudospore is, perhaps, the most fitting name which can beapplied to the so-called spores of the parasiticalConiomycetes.Their peculiar germination, and the production of reproductivebodies on the germ tubes, prove their analogy to some extentwith the prothallus of other cryptogams, and necessitate theuse of some term to distinguish them from such spores as arereproductive without the intervention of a promycelium. The[127]differences between these pseudospores in the several genera areconfined in some instances to their septation, in others to theirmode of development. In theÆcidiacei the pseudospores aremore or less globose, produced in chains within an externalcellular peridium. In theCæomacei they are simple, sometimesproduced in chains, and sometimes free, with or without acaduceous peduncle. In theUstilaginei they are simple, darkcoloured, and occasionally attached in subglobose masses, asinUrocystis andThecaphora, which, are more or less compact.In thePucciniæi the distinctive features of the genera are basedupon the more or less complex nature of the pseudospores, whichare bilocular inPuccinia, trilocular inTriphragmium, multilocularinPhragmidium, &c. In the curious genusPodisoma the septate[128]pseudospores are involved in a gelatinous element. The diffusionof these fruits is more or less complete according to theircompact or pulverulent nature. In some species ofPuccinia thesori are so compact that they remain attached to the leaves longafter they are dead and fallen. In the genusMelampsora, thewedge-shaped winter-pseudospores are not perfected until afterthe dead leaves have for a long time remained and almost rottedon the ground. It is probable that their ultimate diffusion isonly accomplished by the rotting and disintegration of thematrix. In theCæomacei,Ustilaginei, andÆcidiacei the pseudosporesare pulverulent, as in some species ofPuccinia, and areeasily diffused by the motion of the leaves in the wind, or thecontact of passing bodies. Their diffusion in the atmosphereseems to be much less than in the case of theHyphomycetes.By what means such a species asPuccinia malvacearum, which hasvery compact sori, has become within so short a period diffusedover such a wide area, is a problem which in the present stateof our knowledge must remain unsolved. It may be throughminute and plentiful secondary spores.

Fig. 58.—Pseudospores ofThecaphora hyalina.

Fig. 59.—Pseudospores ofPuccinia.

Fig. 60.—Pseudospores ofTriphragmium.

Fig. 61.—Pseudospores ofPhragmidium bulbosum.

Fig. 62.—Melampsora salicina. (Winter fruit.)

Spermatia are very minute delicate bodies found associatedwith many of the epiphyllousConiomycetes, and it has been supposedare produced in conjunction with some of theSphæriacei,but their real function is at present obscure, and the name isapplied rather upon conjecture than knowledge. It is by nomeans improbable that spermatia do exist extensively amongstfungi, but we must wait in patience for the history of theirrelationship.

Trichospores might be applied better, perhaps, thanconidiato the spores which are produced on the threads of theHyphomycetes.Some of them are known to be the conidia of higherplants; but as this is by no means the case with all, it would beassuming too much to give the name of conidia to the whole.By whatever name they may be called, the spores of theHyphomycetes are of quite a different type from any yet mentioned,approximating, perhaps, most closely to the basidiosporesof theHymenomycetes in some, andGasteromycetes in others;as, for instance, in theSepedoniei and theTrichodermacei. The[129]form of the spores and their size differ materially, as well as themanner in which they are produced on the threads. In manythey are very minute and profuse, but larger and less plentifulin theDematiei than in theMucedines. The spores of somespecies ofHelminthosporium are large and multiseptate, callingto mind the spores of theMelanconiei. Others are very curious,being stellate inTriposporium, circinate inHelicoma andHelicocoryne,angular inGonatosporium, and ciliate inMenispora ciliata.Some are produced singly and some in chains, and in somethe threads are nearly obsolete. InPeronospora, it has beendemonstrated that certain species produce minute zoosporesfrom the so-called spores. The dissemination of the minutespores of theMucedines through the air is undoubted; rain alsocertainly assists not only in the dispersion of the spores inthis as in other groups, but also in the production of zoosporeswhich require moisture for that purpose. The form of thethreads, and the mode of attachmentof the spores, is far more variableamongst theMucedines than the formof the spores, but the latter are in allinstances so slightly attached to theirsupports as to be dissevered by theleast motion. This aids also in thediffusion of the spores through theatmosphere.

Fig. 63.—Spores ofHelicocoryne.

Sporangia are produced in thePhysomycetes usually on the tips orbranches of delicate threads, and these when mature dehisce andset free the minute sporidia. These are so small and uniformin their character that they require but a passing mention.The method of diffusion agrees much with that of theMucedines,the walls of the sporangia being usually so thin and delicateas to be easily ruptured. Other modes of fructification prevail insome species by the production of cysts, which are the result ofconjugation of the threads. These bodies are for the most partfurnished with thicker and more resistant walls, and the diffusionof their contents will be regulated by other circumstances than[130]those which influence the dispersion of the minute sporidia fromthe terminal cysts. Probably they are more perennial in theircharacter, and are assimilated more to the oogonia ofCystopusandPeronospora, being rather of the nature of resting spores,inasmuch as the same threads usually bear the terminal fruits.

Fig. 64.—Sporidium ofGenea verrucosa.

Fig. 65.—Alveolate sporidium ofTuber.

Thecaspores is a term which may be applied generally to allsporidia produced in asci, but these are in turn so innumerableand variable that it will be necessary to treat of some of thegroups individually. TheThecaspores, for instance, of theTuberaceioffer several features whereby they may be distinguishedfrom other thecaspores. The asci in which these sporidia aregenerated mostly partake of a broadly saccate, ovate form. Thenumber of sporidia contained in an individual ascus is usuallyless than in the majority of theAscomycetes, and the sporidiaapproximate more nearly to the globose form. Usually, also,they are comparatively large. Many have been figured byCorda[C] and Tulasne.[D] Three types of spores may be said toprevail in theTuberacei: the smooth spored,the warted or spinulose, and the areolate. Thefirst of these may be represented by theStephensiabombycina, in which the globosesporidia are quite smooth and colourless.The warted sporidia may be observed inGenea verrucosa, the spinulose inTubernitidum, and the areolate are present inTuber æstivum andTuber excavatum, in which the epispore is divided into polygonalalveoli, bounded by thin, membranaceous, prominentpartitions. This form of sporidium isvery beautiful. In all no special provision ismade for the dissemination of the sporidia,as, from their subterranean habit, none wouldbe available save the ultimate dissolutionof the external integuments. As they aregreedily devoured by several animals, it ispossible that they may be dispersed through the excrements.

In thePerisporiacei the perithecium has no proper orifice, orostiolum, for the discharge of the mature sporidia, which areusually small, and are disseminated by the irregular rupture ofthe somewhat fragile conceptacles. The asci are usually moreor less saccate, and the sporidia approximate to a globose form.The asci are often very diffluent. InPerisporium vulgare theovate brown sporidia are at first, and for some time, attachedtogether in fours in a concatenate or beaded manner. In somespecies ofErysiphei the conceptacle enclosesbut a single sporangium, in othersseveral, which are attached together at thebase. In some species the sporangia containtwo, in others four, in others eight, and inothers numerous sporidia. InChætomiumthe asci are cylindrical, and in most casesthe coloured sporidia are lemon-shaped.When the conceptacles are fully matured,it is commonly the case that the asci areabsorbed and the sporidia are free in theinterior of the conceptacles.

Fig. 66.—Asci, sporidia, and paraphyses ofAscobolus (Boudier).

Of the fleshyDiscomycetes the genusPeziza may be taken as the type. If thestructure which prevails in this genus bebrought to mind, it will be rememberedthat the hymenium lines an expanded cup,and that the asci are packed together, sideby side, with their apices outwards, andtheir bases attached to a substratum of cellswhich form the inner layer of the receptacle.The sporidia are usually eight ineach ascus, either arranged in single ordouble rows, or irregularly grouped together.The asci are produced in succession;the later, pressing themselves upwardsbetween those previously developed, causethe rupture of the mature asci at the apex and the ejection ofthe sporidia with considerable force. When a largePeziza is[132]observed for a time a whitish cloud will be seen to rise suddenlyfrom the surface of the disc, which is repeated again and againwhenever the specimen is moved. This cloud consists ofsporidia ejected simultaneously from several asci. Sometimesthe ejected sporidia lie like frost on the surface of the disc.Theories have been devised to account for this sudden extrusionof the sporidia, inAscobolus, and a few species ofPeziza,of the asci also, the most feasible one being the successivegrowth of the asci; contraction of the cup may also assist, aswell as some other less potent causes. It may be remarkedhere that the sporidia inPeziza andHelotium are mostly colourless,whilst inAscobolus they pass through pink to violet, ordark brown, and the epispore, which is of a waxy nature, becomesfissured in a more or less reticulated manner.

Fig. 67.—Sporidium ofOstreichnion Americanum.

The sporidia inHysterium proper are usually coloured, oftenmultiseptate, sometimes fenestrate, and occasionally of considerablesize. There is no evidence that the sporidia are everexcluded in the same manner as inPeziza,the lips closing over the disc so much as toprevent this. The diffusion of the sporidiaprobably depends on the dissolution of theasci, and hence they will not be widelydispersed, unless, perhaps, by the action ofrain.

InTympanis, asci of two kinds have beenobserved in some species; one kind containingan indefinite number of very minutebodies resembling spermatia, and the otheroctosporous, containing sporidia of the usualtype.

TheSphæriacei include an almost infinite variety in the formand character of the sporidia. Some of these are indefinite inthe number contained in an ascus, although the majority areeight, and a few less. In the generaTorrubia andHypocrea thestructure differs somewhat from other groups, inasmuch as inthe former the long thread-like sporidia break up into shortjoints, and in the latter the ascus contains sixteen subglobose or[133]subquadrate sporidia. Other species contain linear sporidia,which are often the length of the ascus, and may either be simpleor septate. InSphæria ulnaspora the sporidia are abruptly bentat the second joint. Shorter fusiform sporidia are by no meansuncommon, varying in the number of septa, and in constrictionat the joints in different species. Elliptic or ovate sporidia arecommon, as are those of the peculiar form which may be termedsausage-shaped. These are either hyaline or coloured of someshade of brown. Coloured sporidia of this kind are common inXylaria andHypoxylon, as well as in certain species of the sectionSuperficiales. Coloured sporidia are often large and beautiful:they are mostly of an elongated, elliptical form, or fusiform. Asnoteworthy may be mentioned the sporidia ofMelanconis lanciformis,[134]those ofValsa profusa, and some species ofMassaria,the latter being at first invested with a hyaline coat. Somecoloured sporidia have hyaline appendages at each extremity, asinMelanconis Berkeleii, and an allied species,Melanconis bicornis,from the United States, also some dungSphæriæ, asS. fimiseda,included under the proposed genusSordaria.[E] Hyaline sporidiaoccasionally exhibit a delicate bristle-like appendage at eachextremity, as in theValsa thelebola, or with two additional ciliaat the central constriction, as inValsa taleola. A peculiar formof sporidium is present in certain species ofSphæria found ondung, for which the generic name ofSporormia has been proposed,[135]in which the sporidium (as inPerisporium vulgare)consists of four coloured ovate joints, which ultimately separate.Multiseptate fenestrate sporidia are not uncommon inCucurbitariaandPleospora, as well as inValsa fenestrata and some otherspecies. In the North AmericanSphæria putaminum the sporidiaare extraordinarily large.

Fig. 68.—Ascus and sporidia ofHypocrea.	Fig. 69.—Sporidium ofSphæria ulnaspora.
Fig. 70.—Sporidia ofValsa profusa (Currey).	Fig. 71.—Sporidia ofMassaria fœdans. × 400.
Fig. 72.—Sporidium ofMelanconis bicornis, Cooke.	Fig. 73.—Caudate sporidia ofSphæria fimiseda.
Fig. 74.—Sporidia ofValsa thelebola.	Fig. 75.—Sporidia ofValsa taleola. × 400.
Fig. 76.—Sporidium ofSporormia intermedia.	Fig. 77.—Asci and sporidia ofSphæria (Pleospora)herbarum.

Fig. 78.—Sporidium ofSphæria putaminum. × 400.

The dissemination of the sporidiamay, from identity of structure in theperithecium, be deemed to follow a likemethod in all. When mature, they arein a great measure expelled from themouth of the perithecia, as is evidentin species with large dark sporidia,such as exist in the generaHypoxylon,Melanconis, andMassaria. In thesegenera the sporidia, on maturity, maybe observed blackening the matrixround the mouths of the perithecia.As moisture has an evident effect in producing an expulsion[136]of sporidia by swelling the gelatinous nucleus, it maybe assumed that this is one of the causes of expulsion, andtherefore of aids to dissemination. WhenSphæriæ are submittedto extra moisture, either by placing the twig which bears themon damp sand, or dipping one end in a vessel of water, thesporidia will exude and form a gelatinous bead at the orifice.There may be other methods, and possibly the successive productionof new asci may also be one, and the increase in bulkby growth of the sporidia another; but of this the evidence isscanty.

Finally,Oogonia may be mentioned as occurring in suchgenera asPeronospora amongst moulds,Cystopus amongstUredines, and theSaprolegniaceæ amongst thePhysomycetes.The zoospores being furnished with vibratile cilia, are for sometime active, and need only water in which to disseminate themselves,and this is furnished by rain.

We have briefly indicated the characteristics of some of themore important types of spores to be found in fungi, and someof the modes by which it is known, or presumed, that theirdissemination takes place. In this summary we have been compelledto rest content with suggestions, since an exhaustive essaywould have occupied considerable space. The variability in thefruit of fungi, in so far as we have failed to demonstrate, will befound exhibited in the illustrated works devoted more especiallyto the minute species.[F]

In describing the structure of these organisms in a previouschapter, the modes of germination and growth from the sporeshave been purposely excluded and reserved for the present. Itmay be assumed that the reader, having followed us to thispoint, is prepared for our observations by some knowledge ofthe chief features of structure in the principal groups, and of themain distinctions in the classification, or at least sufficient toobviate any repetition here. In very many species it is by nomeans difficult to induce germination of the spores, whilst inothers success is by no means certain.

M. de Seynes made theHymenomycetes an especial object ofstudy,[A] but he can give us no information on the germinationand growth of the spore. Hitherto almost nothing is positivelyknown. As to the form of the spore, it is always at firstspherical, which it retains for a long time, while attached tothe basidia, and in some species, but rarely, this form is final, asinAg. terreus, &c. The most usual form is either ovoid or regularlyelliptic. All theCoprini have the spores oval, ovoid, moreor less elongated or attenuated from the hilum, which is moretranslucent than the rest of the spore. This last form is rathergeneral amongst the Leucospores, inAmanita,Lepiota, &c. Atother times the spores are fusiform, with regularly attenuatedextremities, as inAg. ermineus, Fr., or with obtuse extremities, as[138]inAg. rutilans, Sch. InHygrophorus they are rather irregular,reniform, or compressed in the centre all round. Hoffmann[B] hasgiven a figure taken fromAg. chlorophanus, and Seynes verifiedit uponAg. ceraceus, Sow. (See figures on page 121.)

The exospore is sometimes roughened, with more or less projectingwarts, as may be seen inRussula, which much resemblesLactarius in this as in some other particulars. The spores oftheDermini and theHyporhodii often differ much from thesphærical form. InAg. pluteus, Fr., andAg. phaiocephalus, Bull,there is already a commencement of the polygonal form, but theangles are much rounded. It is inAg. sericeus,Ag. rubellus,&c., that the polygonal form becomes most distinct. InDerminithe angles are more or less pronounced, and become rather acuteinAg. murinus, Sow., andAg. ramosus, Bull. The passage fromone to the other may be seen in the stellate form of the conidiaofNyctalis.

It is almost always the external membrane that is coloured,which is subject to as much variation as the form. The morefine and more delicate shades are of rose, yellow-dun or yellow,violet, ashy-grey, clear fawn colour, yellow-orange, olive-green,brick-red, cinnamon-brown, reddish-brown, up to sepia-blackand other combinations. It is only by the microscopeand transparency that one can make sure of these tints; upona sufficient quantity of agglomerated spores the colour may bedistinguished by the naked eye. Colour, which has only a slightimportance when considered in connection with other organs,acquires much in the spores, as a basis of classification.

With the growth of Agarics from the mycelium, or spawn, weare not deficient in information, but what are the conditionsnecessary to cause the spores themselves to germinate before oureyes and produce this mycelium is but too obscure. In the cultivatedspecies we proceed on the assumption that the spores havepassed a period of probation in the intestines of the horse, andby this process have acquired a germinating power, so that whenexpelled we have only to collect them, and the excrement in which[139]they are concealed, and we shall secure a crop.[C] As to otherspecies, we know that hitherto all attempts to solve the mysteryof germination and cultivation has failed. There are severalspecies which it would be most desirable to cultivate if the conditionscould be discovered which are essential to germination.[D]In the same manner theBoleti andHydnei—in fact, all otherhymenomycetal fungi, with the exception of theTremellini—stillrequire to be interrogated by persevering experiment and closeinquiry as to their mode of germination, but more especially asto the essential conditions under which alone a fruitful myceliumis produced.

Fig. 79.—(a) Basidia and spores ofExidia spiculosa; (b) Germinating spore.

The germination of the spore has beenobserved in some of theTremellini.Tulasne described it inTremella violacea.[E]These spores are white, unilocular,and filled with a plastic matterof homogeneous appearance. From someportion of their surface an elongatedgerm filament is produced, into whichthe contents of the reproductive cell passuntil quite exhausted. Other spores,perhaps more abundant, have a verydifferent kind of vegetation. Fromtheir convex side, more rarely from theouter edge, these particular spores emita conical process, generally shorter thanthemselves, and directed perpendicularlyto the axis of their figure. This appendagebecomes filled with protoplasm at the expense of the[140]spore, and its free and pointed extremity finally dilated intoa sac, at first globose and empty. This afterwards admitsinto its cavity the plastic matter contained in its support,and, increasing, takes exactly the form of a new spore,without, however, quite equalling in size the primary ormother spore. The spore of the new formation long retains itspedicel, and the mother spore which produced it, but theselatter organs are then entirely empty and extremely transparent.Sometimes two secondary spores are thus engendered from thesame spore, and their pedicels may be implanted on the same oron different sides, so as to be parallel in the former case, andgrowing in opposite directions in the latter. The fate of thesesecondary spores was not determined.

Fig. 80.—Germinating spore and (a) corpuscles ofDacrymyces deliquescens.

InDacrymyces deliquescens are found mingled amongst thespores immense numbers of small round or ovoid unilocularbodies, without appendages of any kind, which long puzzledmycologists. Tulasne ascertained that they are derived fromthe spores of this fungus when they have become free, and reston the surface of the hymenium. Each ofthe cells of the spore emits exteriorly oneor several of these corpuscles, supported onvery short slender pedicels, which remainafter the corpuscles are detached fromthem. This latter circumstance evidencesthat new corpuscles succeed the firstbornone on each pedicel as long as there remainsany plastic matter within the spore. Thelatter, in fact, in consequence of thislabour of production, becomes graduallyemptied, and yet preserves the generativepedicels of the corpuscles, even when it no longer contains anysolid or coloured matter. These pedicels are not all in the sameplane, as may be ascertained by turning the spore on its longitudinalaxis; but it often seems to be so when they are lookedat in profile, on account of the very slight distance which thenseparates them one from another. It will also be remarked thatthey are in this case often implanted all on the same side of the[141]reproductive body, and most often on its convex side. Theirfecundity is exhausted with the plastic contents of the spore.The corpuscles, when placed in the most favourable conditions,have never given the least sign of vegetation; they have alsoremained for a long time in water without experiencing anyappreciable alteration.

All the individuals ofDacrymyces deliquescens do not producethese corpuscles in the same abundance; those which bear themost are recognizable by the pale tint of the reproductive dustwith which they are covered; in others, where this dust preservesits golden appearance, only a few corpuscles are found. Thespores which produce corpuscles do not appear at all apt togerminate. On the other hand, multitudes of spores will germinatewhich had not produced any corpuscles. Tulasne remarkson this, that these observations would authorize us to think thatall spores, though perfectly identical to our eyes, have not,without distinction, the same fate, nor doubtless the same nature;and, in the second place, that these two kinds of bodies, if theyare not always isolated, yet are most frequently met with ondistinct individuals. This author claims for the corpuscles inquestion that they are spermatia, and thinks that their origin isonly so far unusual in that they proceed from veritable spores.

The whole of theGasteromycetes have as yet to be challengedas to the mode and conditions of germination and development.It is probable that these will not materially differ from thosewhich prevail inHymenomycetes.

The germination inÆcidium has been followed out by Tulasne,[F]either by placing the pseudospores in a drop of water, or confiningthem in a moist atmosphere, or by placing the leaves on whichtheÆcidium flourishes upon water. The pseudospores plungedin water germinated more readily than the others. If the conditionswere favourable, germination would take place in a fewhours.Æcidium Ranunculacearum, D. C., on leaves of figwort,gives rarely more than one germinating filament, which soonattains three times the length of the diameter of the pseudospore.This filament generally remains simple, sometimes torulose, and[142]distorted in a long spire. Sometimes it has been seen dividedinto two branches, nearly equal to each other. The spore ingerminating empties itself of its plastic contents, contracts, anddiminishes in size. The pseudospores ofÆcidium crassum, P.,emit three long filaments, which describe spirals, imitating thetwistings of the stem of a bean or bindweed. InÆcidium Violæ,Schum, one filament is produced, which frequently rolls up itsanterior extremity into a spire, but more often this same extremityrises in a large ovoid, irregular vesicle, which continues the axisof the filament, or makes with it a more or less decided angle.In whatever manner placed, this vesicle attracts to it all theorange protoplasm, and hardly does this become settled andcomplete before the vesicle becomes the starting point of a newdevelopment, for it begins to produce at its apex a filament,more slender than the previous one, stiff, and unbranched.

Fig. 81.—Germination ofÆcidium Euphorbia (sylvaticæ), Tulasne.

According to M. Tulasne, the germination of the pseudosporesofÆcidium Euphorbiæ onEuphorbia sylvatica differ in somerespects from the preceding. When droppedupon water these spores very soon emit ashort tube, which ordinarily curves in anarch or circle, almost from its origin, attaininga length of from three to six times thediameter of the spore; then this tube givesrise to four spicules, each of which producesa small obovate or reniform sporule;the generation of these sporules absorbs allthe plastic matter contained in the germ-tube,which permits of the observation thatit was divided into four cells correspondingwith the number of spicules. Thesesporules germinate very rapidly from anindefinite point of their surface, emitting afiliform process, which is flexuous and verydelicate, not extending more in length than three times that ofthe long axis of the sporule, often less, reproducing at itssummit a new sporule, differing in form and size from thatwhich preceded it. This sporule of the second formation becomes[143]at its apex a vital centre, and sprouts one or more linearbuds, of which the elongation is occasionally interrupted by theformation of vesicular swellings. As Tulasne observes, thepseudospores of theÆcidium and the greater number of Uredinesare easily wetted with water before arriving at maturity; butwhen they are ripe, on the contrary, they appear to be clothedwith a greasy matter which protects them from the liquid,forcing them almost all to rest on the surface.

The pseudospores ofRœstelia are produced in strings or chaplets,as inÆcidium, with this difference, that instead of beingcontiguous they are separated by narrow isthmuses. The ripepseudospores are enveloped in a thick tegument, of a dark browncolour. They germinate readily on water, producing a filamentfifteen times as long as the diameter of the spore. This filamentis sometimes rolled or curved. Towards its extremity it exhibitsprotuberances which resemble the rudiments of ramuli, or theyterminate in a vesicle which gives rise to a slender filament.The tegument of these pseudospores, above all in those whichhave germinated, and have consequently become more transparent,it is easy to see has many pores, or round ostioles.

InPeridermium the pseudospores, when dropped upon water,germinate at any point of their surface. Sometimes two unequalfilaments issue from the same spore. After forty-eight hoursof vegetation in the air, the greater part had already emitted amultitude of thick little branches, themselves either simple orbranched, giving to the filaments a peculiar aspect. Tulasne didnot on any occasion observe the formation of secondary spores.

Fig. 82.—Germinating pseudospores of (b)Coleosporium Sonchi; (s s) secondary spores, or sporules (Tulasne).

In the Uredines proper the germination seems to be somewhatsimilar, or at least not offering sufficient differences towarrant special reference inUredo,Trichobasis,Lecythea, &c.InColeosporium there are two kinds of spores, one kind consistingof pulverulent single cells, and the other of elongated septatecells, which break up into obovate joints. Soon after thematurity of the pulverulent spores, each begins to emit a longtube, which is habitually simple, and produces at its summit areproductive cellule, or reniform sporule. The orange protoplasmpasses along the colourless tubes to the terminal sporule at the[144]end of its vegetation. The two forms of spores in this genusare constantly found on the same leaf, and in the same pulvinule,but generally the pulverulent spores abound at the commencementof the summer. The reniform sporules begin to germinatein a great number as soon as they are free; some few extend afilament which remains simple and uniform, but more commonlyit forms at its extremity a second sporule. If this does notbecome isolated, to play an independent life, the filament iscontinued, and new vesicles are repeated many times.

Fig. 83.—Germinating pseudospore (b) ofMelampsora betulina (Tulasne).

InMelampsora the summer spores are of theLecythea type,and were included in that genus till their relation withMelampsorawas clearly made out. The winter spores are in solidpulvinules, and their fructification takes place towards the endof winter or in the spring. This phenomenon consists in the[145]production of cylindrical tubes, which start from the upperextremity of the wedge-shaped spores, or more rarely from thebase. These tubes are straight or twisted, simple or bifurcated,and each of them very soon emits four monosporous spicules, atthe same time that they become septate. The sporules are inthis instance globose.

Fig. 84.—Germinating pseudospore ofUromyce appendiculatus. (Tulasne.)

InUromyces germination follows preciselythe same type as that of the upper cell ofPuccinia; in fact, Tulasne states that it isvery difficult to say in what they differ fromthePucciniæ which are accidentally unilocular.

InCystopus a more complex method prevails,which will be examined more closelyhereafter.

Fig. 85.—Germinating pseudospore ofPuccinia Moliniæ. (Tulasne.)

InPuccinia, as already observed whendescribing their structure, the pseudosporesare two-celled. From the pores of each cell,which are near the central septum, springsa clavate tube, which attains two or threetimes the total length of the fruit, and ofwhich the very obtuse extremity curvesmore or less in the manner of a crozier.[G]This tube, making a perfectly uncolouredtransparent membrane, is filled with agranular and very pale plastic matter atthe expense of the generative cell, which issoon rendered vacant; then it gives rise to four spicules, usuallyon the same side, and at the summit of these produces a reniformcellule. The four sporules so engendered exhaust all theprotoplasm at first contained in the generative cell, so that theirunited capacity proves to be evidently much insufficient to containit, the more so as it leads to the belief that this matterundergoes as it condenses an elaboration which diminishes itssize. In all cases the spicule originates before the sporule whichit carries, and also attains its full length when the sporule appears.[146]The form of the latter is at first globular, then ellipsoid,and more or less curved. All these phases of vegetation areaccomplished in less than twelve hours, and if the spore ismature and ready for germination,it is sufficient to provoke itby keeping the pseudospores in ahumid atmosphere. During thisprocess the two cells do not separate,nor does one commence germinationbefore the other, butboth simultaneously. When thesporules are produced, the protospore,somewhat analogous to aprothallus, has performed itsfunctions and decays. Towardsthe time of the falling of thesporules they are nearly alldivided into four unequal cellsby transverse and parallel septa.These sporules in time produce, from any point on their surface,a filament, which reproduces a new sporule, resembling the first,but generally smaller. Thissporule of the second generationordinarily detaches itselffrom its support before germinating.

Fig. 86.—Germinating pseudospore ofTriphragmium ulmariæ (Tulasne.)

The pseudospores ofTriphragmiumulmariæ have been seen inApril germinating on old leavesof the meadowsweet which survivedthe winter, whilst at thesame time new tufts of the sporeswere being developed on theleaves of the year. These fruitsof the spring vegetation wouldnot germinate the same year.Each cell in germination emits a long cylindrical filament, containing[147]a brownish protoplasm, on which four spicules, bearingas many sporules, are generated.

Fig. 87.—Germinating pseudospore ofPhragmidium bulbosum. (Tulasne.)

The germination of the black fruits ofPhragmidium only appearsto take place in the spring. It greatly resembles that inPuccinia, except that the filament is shorter, and the sporulesare spherical and orange-coloured, instead of being kidney-shapedand pale. In the species found on the leaves of thecommon bramble, the filament emitted by each cell attains threeor four times the length of the fruit. Thegranular orange protoplasm which fills itpasses ere long into the sporules, whichare engendered at the extremity of pointedspicules. After the long warty fruits areemptied of their contents they still seemas dark as before, but the pores which arepierced in the sides, through which thegerminating filaments have proceeded, aremore distinctly visible.

It will be observed that throughout allthese allied genera ofUromyces,Puccinia,Triphragmium, andPhragmidium the sametype of germination prevails, which confirmsthe accuracy of their classification together,and renders still less probable the supposedaffinity ofPhragmidium withSporidesmium,which was at one time held byvery astute mycologists, but which is nowabandoned. This study of germinationleads also to a very definite conclusion with regard to the genusUromyces—that it is much more closely related toPuccinia andits immediate allies than to other unicellular Uredines.

Fig. 88.—Germinating pseudospores ofPodisoma Juniperi. (Tulasne)

The germination of the pseudospores of the gelatinous Uredinesof the genusPodisoma was studied by Tulasne.[H] These[148]pretended spores, he writes, are formed of two large conical cells,opposed by their base and easily separating. They vary in length.The membrane of which they are formed is thin and completelycolourless in most of them, though much thicker and colouredbrown in others. It is principally the spores with thin membranesthat emit from near the middle very obtuse tubes, intowhich by degrees, as they elongate, the contents of the parentutricles pass. Each of the two cells of the supposed spore mayoriginate near its base four of these tubes, opposed to each otherat their point of origin, and their subsequent direction; but it israther rare for eight tubes, two by two, to decussate from thesame spore or basidium. Usually there are only two or threewhich are completely developed, and these tend together towardsthe surface of the fungus, which they pass, and expand at libertyin the air. The tubes generally become thicker by degrees asthey elongate, some only slightly exceeding the length of theprotospores. Others attain three or four times that length,according to the greater or less distance between the protosporeand the surface of the plant. In the longest tubes it is easy toobserve how the colouring matter passes to their outer extremity,[149]leaving the portion nearest to the parent cell colourless andlifeless. When nearly attaining their ultimate dimensions, allthe tubes are divided towards their outer extremity by transversesepta into unequal cells; then simple and solitary processes, ofvariable length and form, but attenuated upwards, proceed fromeach segment of the initial tube, and produce at their extremityan oval spore (teleutospore, Tul.), which is slightly curved andunilocular. These spores absorb all the orange endochrome fromthe original tubes. They appear in immense numbers on thesurface of the fungus, and when detached from their spiculesfall upon the ground or on any object which may be beneaththem. So freely are they deposited that they may be collectedon paper, or a slip of glass, like a fine gold-coloured powder.Again, these secondary spores (teleutospores) are capable ofgermination, and many of them will be found to have germinatedon the surface of thePodisoma whence they originated. Thegerm filament which they produce springs habitually from theside, at a short distance from the hilum, which indicates thepoint of attachment to the original spicule. These filamentswill attain to from fifteen to twenty times the diameter of thespore in length before branching, and are in themselves exceedinglydelicate. The tubes which issue from the primary spores(protospores, Tul.) are not always simple, but sometimes forked;and the cells which are ultimately formed at their extremities,though producing filiform processes, do not always generatesecondary spores (teleutospores) at their apices. This mode ofgermination, it will be seen, resembles greatly that which takesplace inPuccinia.

Fig. 89.—Germinating pseudospore (g) ofTilletia caries with secondary spores in conjugation. (Tul.)

The germination of the Ustilagines was in part examined byTulasne, but since has received accessions through the laboursof Dr. A. Fischer von Waldheim.[I] Nothing, however, of anyimportance is added to our knowledge of the germination ofTilletia, which was made known as early as 1847.[J] After some[150]days a little obtuse tube is protruded through the epispore,bearing at its apex long fusiform bodies, which are the sporulesof the first generation. These conjugate by means of shorttransverse tubes, after the manner of the threads ofZygnema.Afterwards long ellipticalsporules of the second generationare produced on shortpedicels by the conjugatedfusiform bodies of the firstgeneration. (Fig. 89,ss.)Ultimately these sporules ofthe second generation germinate,and generate, on shortspicules, similar sporules of athird generation. (Fig. 89,st.)

Fig. 90.—Pseudospore ofUstilago receptaculorum in germination, and secondary spores in conjugation. (Tul.)

InUstilago (flosculorum)germination takes placereadily in warm weather. Thegerm tube is rather smallerat its base than further on. Infrom fifteen to eighteen hours the contents become coarselygranular; at the same time little projections appear on thetube which are narrowed at the base, into which some of theprotoplasm passes. These ultimately mature into sporules.At the same time a terminal sporule generally appears on thethreads. Secondary sporules frequently grow from the primary,which are rather smaller, and these occasionally give rise to athird generation.

InUrocystis (pompholygodes) the germinating tubes springexclusively from the darker central cells of the clusters. Fromthese are developed at their extremity three or four linearbodies, as inTilletia, but after this no further development hasas yet been traced. It may be remarked here that Waldheimobserved similar conjugation of the sporules in some species of[151]Ustilago as have been remarked in the sporules of the firstgeneration inTilletia.

Fig. 91.—Conidia and zoospores ofCystopus candidus;a. conidium with the plasma divided;b. zoospores escaping;c. zoospores escaped from the conidium;d. active zoospores;e. zoospores, having lost their cilia, commencing to germinate.

Returning toCystopus, as the last of the Uredines, we mustbriefly recapitulate the observations made by Professor de Bary,[K]who, by the bye, claims for them an affinity withPeronospora(Mucedines but too well knownin connection with the potatodisease), andnot with the Uredinesand their allies. In thisgenus there are two kinds ofreproductive organs, those producedon the surface of the plantbursting through the cuticle inwhite pustules, and which DeBary termsconidia, which aregenerated in chains, and certainglobose bodies termedoogonia, which are developed on themycelium in the internal tissues of the foster plant. When theconidia are sown on water they rapidly absorb the moisture, andswell; the centre of one of theextremities soon becomes a largeobtuse papilla resembling theneck of a bottle. This is filledwith a granular protoplasm, inwhich vacuoles are formed.Soon, however, these vacuolesdisappear, and very fine lines ofdemarcation separate the protoplasminto from five to eightpolyhedric portions, each presentinga little faintly-colouredvacuole in the centre (a). Soonafter this division the papilla at the extremity swells, opens itself,and at the same time the five to eight bodies which had formedin the interior are expelled one by one (b). These are zoospores,[152]which at first take a lenticular form, and group themselves beforethe mouth of the parent cell in a globose mass (c.) Very soon,however, they begin to move, and then vibratile cilia show themselves(d), and by means of these appendages the entire globulemoves in an oscillating manner as one by one the zoosporesdisengage themselves, each becoming isolated and swimmingfreely in the surrounding fluid. The movement is preciselythat of the zoospores of Algæ.

Fig. 92.—Resting spore ofCystopus candidus with zoospores escaped.

The generation of the zoospores commences within from anhour and a half to three hours after the sowing of the conidia onwater. From the oogonia, or resting spores, similar zoospores,but in greater number, are generated in the same manner, andtheir conduct after becoming free is identical. Their movementsin the water usually last from two to threehours, then they abate, the cilia disappear,and the spore becomes immovable, takes aglobose form, and covers itself with amembrane of cellulose. Afterwards thespore emits, from any point whatever of itssurface, a thin, straight or flexuous tube,which attains a length of from two to tentimes the diameter of the spore. The extremitybecomes clavate or swollen, afterthe manner of a vesicle, which receives bydegrees the whole of the protoplasm.

De Bary then proceeds to describe experimentswhich he had performed by watering growing plantswith these zoospores, the result being that the germinatingtubes did not penetrate the epidermis, but entered by thestomates, and there put forth an abundant mycelium whichtraversed the intercellular passages. Altogether the germinationof these conidia or zoospores offers so many differencesfrom the ordinary germination of the Uredines, and is so likethat which prevails inPeronospora, in addition to the fact ofboth genera producing winter spores or oogonia, that we cannotfeel surprised that the learned mycologist who made theseobservations should claim forCystopus an affinity withPeronospora[153]rather than with the plants so long associated with itamongst theConiomycetes.

In passing from these to theMucedines, therefore, we cannotdo so more naturally than by means of that genus of whitemoulds to which we have just alluded. The erect branchedthreads bear at the tip of their branchlets spores, or conidia,which conduct themselves in a like manner to the organs sonamed inCystopus, and oogonia or resting spores developed onthe mycelium within the tissues of the foster plant also giveorigin to similar zoospores.

The conidia are borne upon erect, elongated filaments, originatingfrom the creeping mycelium. These threads are hollow,and rarely septate; the upper portion divided into numerousbranches, and these again are subdivided, the ultimate ramulieach terminated by a single conidium. This body when matureis oval or elliptical, filled with protoplasm, but there is a diversityin their mode of germination. In the greater part, ofwhichP. effusa may be taken as an example, the conidia havethe function of simple spores. Placed in favourable conditions,each of them puts forth a germ-tube, the formation of whichdoes not differ in any essential point from what is known of thespores of the greater part of fungi.

The short oval conidia ofP. gangliformis have little obtusepapillæ at their apex, and it is at this point that germinationcommences.

The conidia ofP. densa are similar, but the germination isdifferent. When placed in a drop of water, under favourablecircumstances, the following changes may be observed in fromfour to six hours. The protoplasm, at first uniformly distributedin all the conidia, appears strewn with semi-lenticular, and nearlyequidistant vacuoles, of which the plane face is immediately incontact with the periphery of the protoplasm. These vacuolesnumber from sixteen to eighteen inP. macrocarpa, but are lessnumerous inP. densa. A short time after the appearance of thevacuoles the entire conidium extends itself so that the papilladisappears. Suddenly it reappears, elongates itself, its attenuatedmembrane vanishes, and the protoplasm is expelled by[154]the narrow opening that remains in place of the papilla. Innormal cases the protoplasm remains united in a single mass thatshows a clear but very delicate outline. When it has reachedthe front of the opening in the conidium, which is thus emptied,the mass remains immovable. InP. densa it is at first of a veryirregular form, but assumes by degrees a regular globose shape.This is deprived of a distinct membrane, the vacuoles that disappearedin the expulsion again become visible, but soon disappearfor a second time. The globule becomes surrounded with amembrane of cellulose, and soon puts out from the point oppositeto the opening of the conidium a thick tube which grows inthe same manner as the germ-tube of the conidia in otherspecies. Sometimes the expulsion of the protoplasm is not completelyaccomplished; a portion of it remaining in the membraneof the conidium detaches itself from the expelled portion, andwhile this is undergoing changes takes the form of a vesicle,which is destroyed with the membrane. It is very rare that theprotoplasm is not evacuated, and that the conidia give out terminalor lateral tubes in the manner that is normal to otherspecies without papillæ. The germination just described doesnot take place unless the conidia are entirely surrounded by water;it is not sufficient that they repose upon its surface. Besides,there is another condition which, without being indispensable,has a sensible influence on the germination ofP. macrocarpa, andthat is the exclusion of light. To ascertain if the light or thedarkness had any influence, two equal sowings were placed sideby side, the one under a clear glass bell, the other under ablackened glass bell. Repeated many times, these experimentsalways gave the same result—germination in from four to sixhours in the conidia under the blackened glass; no change inthose under the clear glass up to the evening. In the morninggermination was completed.

The conidia ofP. umbelliferarum andP. infestans[L] showan analogous structure. These bodies, if their development benormal, become zoosporangia. When they are sown upon water,one sees at the end of some hours the protoplasm divided by[155]very fine lines, and each of the parts furnished with a smallcentral vacuole. Then the papilla of the conidium disappears.In its place appears a rounded opening, by which the parts ofthe protoplasm are expelled rapidly, one after the other. Eachof these, when free, immediately takes the form of a perfectzoospore, and commences to agitate itself. In a few momentsthe sporangium is empty and the spores disappear from the fieldof the microscope.

The zoospores are oval or semi-oval, and inP. infestans thetwo cilia spring from the same point on the inferior border ofthe vacuole. Their number in a sporangium are from six to sixteeninP. infestans, and from six to fourteen inP. umbelliferarum.The movement of the zoospores ceases at the end offrom fifteen to thirty minutes. They become motionless, coverthemselves with a membrane of cellulose, and push out slenderbent germ-tubes which are rarely branched. It is but seldomthat two tubes proceed from the same spore. The same developmentof the zoospores inP. infestans is favoured by theexclusion of the light. Placed in a position moderately lightedor protected by a blackened bell, the conidia very readily producedzoospores.

A second form of germination of the conidia inP. infestans,when sown upon a humid body or on the surface of a drop ofwater, consists in the conidium emitting from its summit asimple tube, the extremity of which swells itself into the formof an oval vesicle, drawing to itself, little by little, all the protoplasmcontained in the conidium. Then it isolates itself fromthe germ-tube by a septum, and takes all the essential characteristicsof the parent conidium. This secondary conidium cansometimes engender a third cellule by a similar process. Thesesecondary and tertiary productions have equally the character ofsporangia. When they are plunged into water, the ordinary productionof zoospores takes place.

Lastly, there is a third mode of germination which the conidiaofP. infestans manifest, and which consists in the conidiumemitting from its summit a simple or branched germ-tube. Thisgrows in a similar manner to the conidia first named as of such[156]species asP. effusa. The conditions which control this formof germination cannot be indicated, since some conidia whichgerminate after this manner will sometimes be found mixedwith others, the majority of which furnish zoospores. It maybe that the conidia themselves are in some sort of abnormalcondition.

In all the species examined the conidia possess the power ofgermination from the moment of their maturity. The youngerthey are the more freely they germinate. They can retain thispower for some days or weeks, provided they are not entirelydried. Dessication in an ordinary temperature seemed sufficientto destroy the faculty of germinating in twenty-four hours, whenthe conidia had been removed from the leaves on which theywere produced. They none of them retained the faculty duringa few months, hence they cannot preserve it during the winter.

The germs ofPeronospora enter the foster plant if the sporesare sown upon a part suitable for the development of theparasite. It is easy to convince one’s self that the mycelium,springing from the penetrating germs, soon takes all thecharacters that are found in the adult state. Besides, whencultivated for some time, conidiiphorous branches can be seengrowing, identical with those to which it owes its origin. Suchcultivation is so readily accomplished that it can be made uponcut leaves preserved fresh in a moist atmosphere.

In the species ofPeronospora that inhabit perennial plants, orannual plants that last through the winter, the mycelium hiddenin the tissues of the foster-plant lasts with it. In the spring itrecommences vegetation, and emits its branches into the newly-formedorgans of its host, there to fructify. ThePeronosporaof the potato is thus perennial by means of its mycelium containedin the browned tissue of the diseased tubers. When inthe spring a diseased potato begins to grow, the mycelium risesin the stalk, and soon betrays itself by blackish spots. Theparasites can fructify abundantly on these little stalks, and inconsequence propagate themselves in the new season by theconidia coming from the vivacious mycelium.

The diseased tubers of the potato always contain the mycelium[157]ofP. infestans, which never fructifies there as long as theskin of the tuber is intact. But when, in cutting the tuber, theparenchyma occupied by the mycelium is exposed to the contactof the air, it covers itself with conidia-bearing branches at theend of from twenty-four to forty-eight hours. Analogous resultsare obtained with the stalks of the potato. It is evident thatin these experiments nothing is changed except the contact ofthe air; the specific conditions particularly remain the same.It appears, therefore, that it is this contact alone which determinesgenerally the production of the conidiiferous branches.[M]

The mode of germination and development in the Mucors hasbeen studied by several observers, but most recently by VanTieghem and Le Monnier.[N] In one of the common forms, theMucor phycomyces of some authors, and thePhycomyces nitensof others, the process is given in detail. In this species germinationwill not take place in ordinary water, but it readily takesplace in orange juice and other media. The spore loses colour,swells, and absorbs fluid around it until double its original sizeand ovoid. Then a thick thread is emitted from one or bothextremities, which elongates and becomes branched in a pinnatemanner. Sometimes the exospore is ruptured and detachedloosely from the germinating spore. After about forty-eighthours from the first sowing, the mycelium will send branchesinto the air, which again become abundantly branched; othershort submerged branches will also remain simple, or have tuft-likeramifications, each terminating in a point, so as to bristlewith spiny hairs. In two or three days abruptly swollenbranches, of a club shape, will make their appearance on thethreads both in the air and in the fluid. Sometimes thesebranches are prolonged into an equal number of sporangia-bearingthreads, but most frequently they divide first at theirswollen summits into numerous branches, of which usually one,[158]sometimes two or three, develop into sporangia-bearing threads,while the rest are short, pointed, and form a tuft of rootlets.Sometimes these rootlets reduce themselves to one or morerounded protuberances towards the base of the sporangia-bearingthreads.

Fig. 93.—Zygospores ofMucor phycomyces. (Van Tieghem.)

There are often also a certain number of the brancheswhich had acquired a clavate shape, and do not erectthemselves above the surface, instead of producing a fertilethread, which would seem to have been their first intention,become abruptly attenuated, and are merely prolonged into amycelial filament. Although in other species chlamydosporesare formed in such places on the mycelium, nothing of the kindhas been traced in this species, more than here indicated. Occasionally,when germination is arrested prematurely, certainportions of the hyphæ, in which the protoplasm maintains itsvitality, become partitioned off. This may be interpreted as atendency towards the formation of chlamydospores, but there isno condensation of protoplasm, or investiture with a specialmembrane. Later on this isolated protoplasm is graduallyaltered, separating into somewhat regular ovoid or fusiformgranules, which have, to a certain extent, the appearance of sporesin an ascus, but they seem to be incapable of germination.

Another method of reproduction, not uncommon inMucorini,is described by Van Tieghem in this species. Conjugatingthreads on the substratum by degrees elaborate zygospores, butthese, contrary to the mode in other species, are surrounded bycurious branched processes which emanate from the arcuate cellson either side of the newly-developed zygospore. This systemof reproduction is again noticed more in detail in the chapteron polymorphism.

M. de Seynes has given the details of his examination of thesporidia ofMorchella esculenta during germination.[O] A numberof these sporidia, placed in water in the morning, presented, atnine o’clock of the same evening, a sprout from one of theextremities, measuring half the length of the spore. In themorning of the next day this sprout had augmented, andbecome a filament three or four times as long. The next daythese elongated filaments exhibited some transverse divisionsand some ramifications. On the third day, the germinationbeing more advanced, many more of the sporidia were as completelychanged, and presented, in consequence of the elongation,the appearance of a cylindrical ruffle, the cellular prolongationsarising from the germination having a tendency towards one ofthe extremities of the longer axis of the sporidium, and moreoften to the two opposed extremities, either simultaneously orsuccessively. Out of many hundreds of sporidia examinedduring germination, he had only seen a very few exceptions tothis rule, among which he had encountered the centrifugaltendency to vegetate by two opposed filaments, proving that ifit bears a second by the side of the primal filament situated atone of the poles, a second would also be seen from the side ofthe filament coming from the opposite pole.

Before being submitted to the action of water, the contentsof the sporidia seemed formed of two distinct parts, one bigdrop of yellow oil of the same form as the sporidium, withthe space between it and the cell wall occupied by a clear liquid,more fluid and less refractive, nearly colourless, or at timesslightly roseate. As the membrane absorbed the water by[160]which it was surrounded, the quantity of this clear liquid wasaugmented, and the rosy tint could be more easily distinguished.All the contents of the spore, which up to this time remaineddivided into two parts, presented altogether one aspect, only containingnumerous granulations, nearly of equal size, completelyfilling it, and reaching the inner face of the sporic membrane.

After this time the sporidium augments in size very rapidly,becoming at times irregular, and sometimes even as much asfrom two to three times its original dimensions, then thereappears at the surface, usually at one of the poles of the ellipse,a small prominence, with an extremely fine membrane, whichdoes not appear to separate itself from that which surrounds thesporidium, and it is difficult to say whether it is a prolongationof the internal membrane going across the outside, or simply aprolongation caused by a continuation of tissue of an uniquemembrane. Sometimes there may be seen at the point wherethe primal filament issues from the sporidium a circular mark,which appears to indicate the rupture of the external membrane.From this time another change comes over the contents. Weagain find the yellow oily liquid, now occupying the externalposition, with some drops of colourless or roseate liquid in thecentre, so that the oily liquid and the more limpid fluidinterchange the positions which they occupied previous tothe commencement of germination. Whether these two fluidshave undergone any change in their constitution is difficult todetermine, at all events the oily liquid appears to be less refractiveand more granular, and it may be that it is a product ofnew formation, containing some of the elements of the primitiveoily drop. Having regard to the delicate character of the membraneof the germinating filaments, De Seynes supposed that itmight offer greater facility for the entrance of water by endosmose,and account for the rapid enlargement of the sporidia. Bya series of experiments he became satisfied that this was thecase to a considerable extent, but he adds:—“I cannot helpsupposing that a greater absorption of greasy matter in the cellwhich is the first product of germination raises an objection toan aqueous endosmose. One can also see in this experience a[161]proof of the existence of two special membranes, and so supposethat the germinative cell is the continuation of the internalmembrane, the external membrane alone being susceptible ofabsorbing the liquids, at least with a certain rapidity.”

Fig. 94.—Sporidium ofAscobolus germinating.

In otherDiscomycetes germination takes place in a similarmanner. Boudier[P] narrates that inAscobolus, when once thespore reaches a favourable place, if the circumstances are good,i.e., if the temperature is sufficiently high and the moisturesufficient, it will germinate. The time necessary for this purposeis variable, some hours sufficing for somespecies; those ofA. viridis, for example, germinatein eight or ten hours, doubtless because,being terrestrial, it has in consequence less heat.The spore slightly augments in size, then opens,generally at one or other extremity, sometimes attwo, or at any point on its surface, in order topass the mycelium tubes. At first simple, withoutsepta, and granular in the interior, aboveall at the extremity, these tubes, the rudiment ofthe mycelium, are not long in elongating, inbranching, and later in having partitions. Thesefilaments are always colourless, only the sporemay be coloured, or not. Coemans has describedthem as giving rise to two kinds of conidia,[Q] theone having the form ofTorula, when they giverise to continuous filaments, the other in the formofPenicillium, when they give birth to partitioned filaments.De Seynes could never obtain this result. Many times he had seenthePenicillium glaucum invade his sowings, but he feels confidentthat it had nothing to do with theAscobolus. M. Woronin[R]has detailed some observations on the sexual phenomena whichhe has observed inAscobolus andPeziza, and so far as the scoleciteis concerned these have been confirmed by M. Boudier.

There is no reason for doubt that in other of theDiscomycetesthe germination of the sporidia is very similar to that alreadyseen and described, whilst in thePyrenomycetes, as far as we areaware, although the production of germinating tubes is by nomeans difficult, development has not been traced beyond thisstage.[S]

The existence of some sort of sexual reproduction in Fungi haslong been suspected, although in earlier instances upon insufficientgrounds; but of late years observations have multipliedand facts accumulated which leave no doubt of its existence. IftheSaprolegniæ are left out of the question as disputed Fungi,there still remain a number of well authenticated instances ofthe phenomena of copulation, and many other facts whichindicate some sort of sexual relationship. The precise mannerin which those minute bodies, so common amongst theSphæronemei, which we prefer to call stylospores, performtheir functions is still to a great extent a mystery; yet it isno longer doubted that certain species ofAposphæria,Phoma,Septoria, &c., are only conditions of some species ofSphæria,often developed and matured in close proximity to them on thesame host. InÆcidium,Rœstelia, &c., spermogonia are producedplentifully on or near the same spots on which the fructificationappears, either simultaneously or at a later period.[A] The relationofCytispora toValsa was suspected by Fries very manyyears ago, and, as since demonstrated, with very good reason.All attempts, however, to establish anything like sexual reproductionin the higher forms ofHymenomycetes have at presentbeen unsuccessful; and the same may be said of theGasteromycetes;but inAscomycetes andPhysomycetes instances abound.

We know not whether any importance is to be attached to the[164]views of M. A. S. Œrsted,[B] which have not since been confirmed,but which have been cited with some approval by Professorde Bary, as to a trace of sexual organs inHymenomycetes.He is supposed to have seen inAgaricus variabilis, P., oocystsor elongated reniform cells, which spring up like rudimentarybranches of the filaments of the mycelium, and enclose an abundantprotoplasm, if not even a nucleus. At the base of theseoocysts appear the presumed antheridia, that is to say, one or twoslender filaments, which generally turn their extremities towardsthe oocysts, and which more rarely are applied to them. Then,without ulteriorily undergoing any appreciable modifications, thefertile cell or oocyst becomes enveloped in a network of filamentsof mycelium which proceed from the one which bears it,and this tissue forms the rudiments of the cap. The reality ofsome kind of fecundation in this circumstance, and the mode ofthe phenomena, if there is one, are for the present equally uncertain.If M. Œrsted’s opinion is confirmed, naturally thewhole of the cap will be the product of fecundation. ProbablyKarsten (Bonplandia, 1862, p. 62) saw something similar inAgaricus campestris, but his account is obscure.

Fig. 95.—Zygospore ofMucor phycomyces.

InPhycomyces the organs of reproduction have been subjectedto close examination by Van Tieghem,[C] and although he failedto discover chlamydospores in this, he describes them in otherMucors. In this species, besides the regular sexual development,by means of sporangia, there is a so-called sexual reproductionby means of zygospores, which takes place in this wise.The threads which conjugate to form the zygospores are slenderand erect on the surface of the substratum. Two of thesethreads come into close contact through a considerable length,and clasp each other by alternate protuberances and depressions.Some of the protuberances are prolonged into slender tubes. Atthe same time the free extremities of the threads dilate, and arch[165]over one towards the other until their tops touch like a vice,each limb of which rapidly increases in size. Each of thesearcuate, clavate cells has now a portion of its extremity isolatedby a partition, by means of which a new hemispherical cell isformed at the end of each thread at its point of junction withthe opposed thread. These cells become afterwards cylindricalby pressure, the protoplasm is aggregated into a mass, the doublemembrane at the point of first contact is absorbed, and the twoconfluent masses of protoplasm form a zygospore invested witha tubercular coat and enveloped by the primary wall of the twoconjugating cells. During this formation of the zygospore, thetwo arched cells whence the zygospore originated develop aseries of dichotomous processes in close proximity to the wallswhich separate them from the zygospore. These processesappear at first on one of the arcuate cells in successive order.The first makes its appearance above upon the convex side; thesucceeding ones to the right and left in descending order; thelast is in the concavity beneath. It is only after the developmentof this that the first process appears on the opposite cell, which isfollowed by others in the same order. These dichotomous processesare nothing more than branches developed from the arcuate,or mother cells. During all these changes, while the zygospore[166]enlarges, the wall of the arcuate cells becomes coloured brown.This colouring is more marked on the convex side, and it showsitself first in the cell on which the dichotomous branches arefirst produced, and which retains the darker tint longer than theother. The zone from whence the processes issue, and also theprocesses themselves, have their walls blackened deeply, whilethe walls of the conjugated cells, which continue to clothe thezygospore during the whole of its development, are bluish-black.By pressure, the thin brittle coat which envelopes the zygosporeis ruptured, and the coat of the zygospore exposed, formed of athick cartilaginous membrane, studded with large irregular warts.

The germination of the zygospores in this species has not asyet been observed, but it is probably the same or very similar tothat observed in other species ofMucor. In these the roughtuberculate epispore splits on one side, and its internal coatelongates itself and protrudes as a tube filled with protoplasmand oil globules, terminating in an ordinary sporangium.Usually the amount of nutriment contained in the zygosporeis exhausted by the formation of the terminal sporangium, accordingto Brefeld;[D] but Van Tieghem and Le Monnier remarkthat in their examinations they have often seen a partitionformed at about a third of the length of the principal filamentfrom the base, below which a strong branch is given off, andthis is also terminated by a large sporangium.

Fig. 96.—Zygospore ofRhizopus in different stages. (De Bary.)

De Bary has given a precise account of the formation of thezygospore in another of the Mucors,Rhizopus nigricans, in whichhe says that the filaments which conjugate are solid rampanttubes, which are branched without order and confusedly intermingled.Where two of these filaments meet each of thempushes towards the other an appendage which is at first cylindricaland of the same diameter. From the first these twoprocesses are applied firmly one to the other by their extremities;they increase in size, become clavate, and constitute togethera fusiform body placed across the two conjugated filaments.Between the two halves of this body there exists no constantdifference of size; often they are both perfectly equal. In each[167]there is collected an abundance of protoplasm, and when theyhave attained a certain development the largest extremity ofeach is isolated by a septum from the clavule, which thus becomesthe support or suspender of the copulative cell. The two conjugatedcells of the fusiform body are generally unequal; the oneis a cylinder as long as it is broad, the other is disciform, andits length is only equal to half its breadth. The primitive membraneof the clavule forms between the copulative cells a solidpartition of two membranes, but soon after the cells have becomedefined the medial partition becomes pierced in the centre, andthen soon entirely disappears, so that the two twin cells areconfounded in one single zygospore, which is due to the unionof two more or less similar utricles. After its formation thezygospore still increases considerably in size, and acquires adiameter of more than one-fifth of a millimetre. Its form isgenerally spherical, and flattened on the faces which are unitedto the suspenders, or it resembles a slightly elongated cask.The membrane thickens considerably, and consists at the timeof maturity of two superposed integuments; the exterior orepispore is solid, of a dark blackish-blue colour, smooth on theplane faces in contact with the suspenders, but covered everywhereelse with thick warts, which are hollow beneath. Theendospore is thick and composed of several layers, colourless,and covered with warts, which correspond and fit into those ofthe epispore. The contents of the zygospore are a coarsely[168]granular protoplasm, in which float large oleaginous drops.While the zygospore is increasing in size, the suspender of thesmaller copulative cell becomes a rounded and stipitate utricle,often divided at the base by a septum, and which attains almostto the size of the zygospore. The suspender of the larger copulativecell preserves its primitive form and becomes scarcely anylarger. It is rare that there is not a considerable difference ofsize between the two conjugated cells and the suspenders.[E]

Similar conjugation with like results also takes place inSyzygites megalocarpus. In this species the germination of thezygospores has been observed. If, after a certain time of repose,these bodies are placed on a moist substratum, they emit agerm-like tube, which, without originating a proper mycelium,develops at the expense of the nutritive material stored in thezygospore into a carpophore or fruit bearer, which is many timesdichotomously branched, bearing terminal sporangia characteristicof the species.

It has already been remarked by us that theSaprolegnei areclaimed by some authors as Algæ, whilst we are more disposedto regard them as closely allied to the Mucors, and as theyexhibit in themselves strong evidence in support of the existenceof sexual reproduction, we cannot forbear giving a summary ofwhat has been observed by De Bary and others in this veryinteresting and singular group of plants, to which M. Cornu hasrecently dedicated an exhaustive monograph.[F]

InSaprolegnia monoica, and others, the female organs consistof oogonia—that is to say, of cells which are at first globose andrich in plastic matter, which most generally terminate shortbranches of the mycelium, and which are rarely seen in aninterstitial position. The constitutive membrane of the adultoogonia is reabsorbed in a great many points, and is therepierced with rounded holes. At the same time the plasma isdivided into a larger or smaller number of distinct portions,which are rounded into little spheres, and separate from the[169]walls of the conceptacle in order to group themselves at thecentre, where they float in a watery fluid. These gonospheresare then smooth and bare, with no membrane on their surfaceof the nature of cellulose.

Fig. 97.—Conjugation inAchlya racemosa. (Cornu.)

During the formation of the oogonia there arise from itspedicel or from neighbouring filaments slight cylindrical curvedbranches, sometimes turned round the support of the oogonia,and which all tend towards this organ. Their superior extremityis intimately applied to its wall, then ceases to be elongated,becomes slightly inflated, and is limited below by a partition;it is then an oblong cell, slightlycurved, filled with protoplasm, andintimately applied to the oogonia—infact, an antheridium or organ ofthe male sex. Each oogonium possessesone or several antheridia.Towards the time when the gonospheresare formed it may be observedthat each antheridium sendsto the interior of the oogonia oneor several tubular processes, whichhave crossed its side wall, and whichopen at their extremity in order todischarge their contents. These,while they are flowing out, present some very agile corpuscles,and which, considering their resemblance to those inVaucheria,to which the name of spermatozoids are applied, ought to beconsidered as the fecundating corpuscles. After the evacuationof the antheridia the gonospheres are found to be covered withcellulose; they then constitute so many oospores, with solidwalls. De Bary considers that, bearing in mind analogousphenomena observed inVaucheria, and the direct observationsof Pringsheim,[G] the cellulose membrane on the surface of thegonospheres is only the consequence of a sexual fecundation.

InAchlya dioica the antheridium is cylindrical, the plasmawhich it encloses is divided into particles, which attain nearly[170]the size of the zoospores of the same plant. These particlesbecome globose cells, grouped in the centre of the antheridium.Afterwards the contents of these latter cells become dividedinto numerous bacillary spermatozoids, which first break thewall of their mother cell, and then issue from the antheridium.These rod-like corpuscles, which resemble the spermatozoids inVaucheria, have their movements assisted by a long cilium. Itis presumable that here, as in the Algæ, the spermatozoidsintroduce themselves into the cavity of the oogonium, and unitewith the gonospheres.

Amongst obscure and doubtful bodies are those describedby Pringsheim, which have their origin in thick filaments ortubes, similar to those which form the zoosporangia, and representso many distinct little masses of plasma within anhomogeneous parietal ganglion. The contour of these plasticmasses is soon delineated in a more precise manner. Wesee in their interior some homogeneous granules, whichare at first globose, then oval, and finally travel to theenlarged and ampullæform extremity of the generating tube.There they become rounded or oval cells covered with cellulose,and emit from their surface one or several cylindricalprocesses, which elongate towards the wall of the conceptacle,and pierce it, without, however, ever projecting very far beyondit. At the same time the lacunose protoplasm of each cellbecomes divided into a number of corpuscles, which escape bythe open extremity of the cylindrical neck. They resemble intheir organization and agility the spermatozoids ofAchlya dioica.They soon become motionless in water, and do not germinate.During the development of these organs, the protoplasm of theutricle which contains them offers at first completely normalcharacteristics, and disappears entirely by degrees as theyincrease. De Bary and Pringsheim believe that these organsconstitute the antheridia of the species ofSaprolegnia to whichthey belong.

The oospores of theSaprolegniæ, when arrived at maturity,possess a tolerably thick double integument, consisting of anepispore and an endospore. After a considerable time of repose[171]they give rise to tubular or vesicular germs, which, withoutbeing much elongated, produce zoospores.[H]

De Bary has claimed for the oogonia inCystopus andPeronosporaa kind of fecundation which deserves mention here.[I]These same fruits, he says, which owe their origin to sexualorgans, should bear the names ofoogonia andantheridia, accordingto the terminology proposed by Pringsheim for analogousorgans in the Algæ. The formation of the oogonia, orfemale organs, commences by the terminal or interstitial swellingof the tubes of the mycelium, which increase and take the formof large spherical or oboval cells, and which separate themselvesby septa from the tube which carries them. Their membraneencloses granules of opaque protoplasm, mingled with numerousbulky granules of colourless fatty matter.

Fig. 98.—Conjugation inPeronospora; a. antheridium. (De Bary.)

The branches of the mycelium which do not bear oogoniaapply their obtuse extremities against the growing oogonia;this extremity swells, and, by a transverse partition, separatesitself from the supporting tube. It is the antheridium, or maleorgan, which is formed by this process; it takes the form of anobliquely clavate or obovate cellule, whichis always considerably smaller than theoogonium, and adheres to its walls by aplane or convex area. The slightly thickenedmembrane of the antheridia encloses protoplasmwhich is finely granular. It is seldomthat more than one antheridium appliesitself to an oogonium.

The two organs having together achievedtheir development, the large granules containedin the oogonium accumulate at itscentre to group themselves under the form of an irregularglobule deprived of a proper membrane, and surrounded by abed of almost homogeneous protoplasm. This globule is thegonosphere, or reproductive sphere, which, through the means of[172]fecundation, should become the reproductive body, vegetableegg, or oospore. The gonosphere having been formed, theantheridium shoots out from the centre of its face, close againstthe oogonium, a straight tube, which perforates the walls ofthe female cell, and traversing the protoplasm of its periphery,directs itself to the gonosphere. It ceases to elongate itselfas soon as it touches it, and the gonosphere becomes clothedwith a membrane of cellulose, and takes a regular spheroidalform.

Fig. 99.—Antheridia and oogonium ofPeronospora. (De Bary.)

Considering the great resemblance of these organs with thesexual organs of the Saprolegniæ, whichare closely allied to the Algæ, and ofwhich the sexuality has been proved,De Bary adds, we have no doubt whateverthat the phenomena just describedrepresent an act of fecundation, andthat the tube pushed out by the antheridiumshould be regarded as a fecundatingtube. It is remarkable thatamongst these fungi the tube projected by the antheridiumeffects fecundation only by contact. Its extremity never opens,and we never find antherozoids; on the contrary, the antheridiumpresents, up to the maturity of the oospore, the appearancewhich it presented at the moment of fecundation.

The primitive membrane of the oospore, at first very thin,soon acquires a more sensible thickness, and becomes surroundedby an external layer (epospore), which is formed at the expenseof the protoplasm of the periphery. This disappears in proportionas the epispore attains maturity, and finally there only remainsa quantity of granules, suspended in a transparent wateryfluid. At the period of maturity, the epispore is a slightly thickened,resistant membrane, of a yellowish-brown colour, and finelypunctate. The surface is almost always provided with brownishwarts, which are large and obtuse, sometimes isolated, and sometimesconfluent, forming irregular crests. These warts are composedof cellulose, which reagents colour of a deep blue, whilstthe membrane which bears them preserves its primitive colour.[173]One of the warts, larger than the rest, and recognizable by itscylindrical form, always forms a kind of thick sheath aroundthe fecundating tube. The ripe endospore is a thick, smooth,colourless membrane, composed of cellulose containing a bed offinely granulated protoplasm, which surrounds a great centralvacuole. This oospore, or resting spore, may remain dormantin this state within the tissues of the foster plant for somemonths. Its ultimate development by production of zoosporesis similar to the production of zoospores from conidia, whichit is unnecessary to repeat here. The oospore becomes anoosporangium, and from it at least a hundred germinatingbodies are at length expelled.

Amongst the principal observers of certain phenomena of copulationin cells formed in the earliest stages of theDiscomycetesare Professor de Bary,[J] Dr. Woronin,[K] and Messrs. Tulasne.[L]In theAscobolus pulcherrimus of Crouan, Woronin ascertainedthat the cup derives its origin from a short and flexible tube,thicker than the other branches of the mycelium, and which issoon divided by transverse septa into a series of cells, the successiveincrease of which finally gives to the whole a torulose andunequal appearance. The body thus formed he calls a “vermiformbody.” The same observer also seems to have convincedhimself that there exists always in proximity to this body certainfilaments, the short arched or inflected branches of which, likeso many antheridia, rest their anterior extremities on the utriformcells. This contact seems to communicate to the vermiformbody a special vital energy, which is immediately directed towardsthe production of a somewhat filamentous tissue, on which thehymenium is at a later period developed. This “vermiformbody” of M. Woronin has since come to be recognized underthe name of “scolecite.”

Tulasne observes that this “scolecite” or ringed body can bereadily isolated inAscobolus furfuraceus. When the young receptacles[174]are still spherical and white, and have not attained adiameter exceeding the one-twentieth of a millimetre, it is sufficientto compress them slightly in order to rupture them at thesummit and expel the “scolecite.” This occupies the centreof the little sphere, and is formed of from six to eight cells,curved in the shape of a comma.

InPeziza melanoloma, A. and S., the same observer succeededstill better in his searches after the scolecite, which he remarksis in this species most certainly a lateral branch of the filamentsof the mycelium. This branch is isolated, simple, or forked at ashort distance from its base, and in diameter generally exceedingthat of the filament which bears it. This branch is soon arcuateor bent, and often elongated in describing a spiral, the irregularturns of which are lax or compressed. At the same time itsinterior, at first continuous, becomes divided by transverse septainto eight or ten or more cells. Sometimes this special branchterminates in a crozier shape, which is involved in the bent partof another crozier which terminates a neighbouring filament. Inother cases the growing branch is connected, by its extremity,with that of a hooked branch. These contacts, however, didnot appear to Tulasne to be so much normal as accidental. Butof the importance of the ringed body, or “scolecite,” there wasno room for doubt, as being the certain and habitual rudimentof the fertile cup. In fact, inferior cells are produced from theflexuous filaments which creep about its surface, cover and surroundit on all sides, while joining themselves to each other.At first continuous, then septate, these cells by their union constitutea cellular tissue, which increases little by little until thescolecite is so closely enveloped that only its superior extremitycan be seen. These cellular masses attain a considerable volumebefore the hymenium begins to show itself in a depression oftheir summit. So long as their smallness permits of their beingseen in the field of the microscope, it can be determined thatthey adhere to a single filament of the mycelium by the base ofthe scolecite which remains naked.

Fig. 100.—Conjugation inPeziza omphalodes. (Tulasne.)

Although Tulasne could not satisfy himself of the presenceof any act of copulation inAscobolus furfuraceus, orPeziza[175]melanoloma, he was more successful withPeziza omphalodes.As early as 1860 he recognized the large globose, sessile, andgrouped vesicles which originate the fertile tissue, but did notcomprehend the part which these macrocysts were to perform.Each of these emits from its summit a cylindrical tube, generallyflexuous, but always more or less bent in a crozier shape, sometimesattenuated at the extremity. Thus provided, these utriclesresemble so many tun-shaped, narrow-necked retorts, filled witha granular thick roseate protoplasm. In the middle of these,and from the same filaments, are generated elongated clavatecells, with paler contents, more vacuoles, which Tulasne namesparacysts. These, though produced after themacrocysts, finallyexceed them in height, and seem to carry their summit so as tomeet the crozier-like prolongations. It would be difficult todetermine to which of these two orders of cells belongs theinitiative of conjugation. Sometimes the advance seems to beon one side, and sometimes on the other. However this may be,the meeting of the extremity of theconnecting tube with the summit ofthe neighbouring paracyst is a constantfact, observed over and overagain a hundred times. There is noreal junction between the dissimilarcells above described, except at thevery limited point where they meet,and there a circular perforation maybe discerned at the end, defined by around swelling, which is either barelyvisible or sometimes very decided.Everywhere else the two organs maybe contiguous, or more or less near together,but they are free from any adherence whatever. If theplastic matters contained in the conjugated cells influence oneanother reciprocally, no notable modification in their appearanceresults at first. The large appendiculate cell seems, however, toyield to its consort a portion of the plasma it contains. Onething only can be affirmed from these phenomena, that the conjugated[176]cells, especially the larger, wither and empty themselves,while the upright compressed filaments, which will ultimatelyconstitute the asci, increase and multiply.[M]

Fig. 100a.—Formation of conceptacle inErysiphe

Certain phenomena concerned in the development of theErysiphei belong also to this connection. The mycelium ofErysiphe cichoracearum, like that of other species, consists ofbranched filaments, crossed in all directions, which adhere asthey climb to the epidermis of the plant on which the funguslives as a parasite. The perithecia are engendered where twofilaments cross each other. These swell slightly at this point,and each emits a process which imitates a nascent branch, andremains upright on the surface of the epidermis. The processoriginating from the inferior filament soon acquires an oval formand a diameter double that of the filament; then it becomesisolated from it by a septum, and constitutes a distinct cell,which De Bary[N] terms an oocyst. The appendage which proceedsfrom the inferior filament always adheres intimately tothis cell, and elongates into a slender cylindrical tube, which[177]terminates in an obtuse manner at the summit of the same cell.At its base it is also limited by a septum, and soon after anotherappears a little below its extremity at a point indicated beforehandby a constriction. This new septum defines a terminalshort obtuse cell, the antheridium, which is thus borne on anarrow tube like a sort of pedicel. Immediately after theformation of the antheridia new productions show themselves,both around the oocyst and within it. Underneath this cell eightor ten tubes are seen to spring from the filament which bears it;these join themselves by the sides to each other and to the pedicelof the antheridium, while they apply their inner face to theoocyst, above which their extremities soon meet. Each of thetubes is then divided by transverse septa into two or three distinctcells, and in this manner the cellular walls of the peritheciacome into existence.

During this time the oocyst enlarges and divides, withoutits being possible precisely to determine the way in which ithappens, into a central cell and an outer layer, ordinarilysimple, of smaller cells, contiguous to the general envelopingwall. The central cell becomes the single ascus, which ischaracteristic of the species, and the layer which surrounds itconstitutes the inner wall of its perithecium. The onlychanges afterwards observed are the increase in size of theperithecium, the production of the root-like filaments whichproceed from its outer wall, the brown tint which it assumes,and finally the formation of the sporidia in the ascus. Theantheridium remains for a long time recognizable without undergoingany essential modification, but the dark colour of theperithecium soon hides it from the observer’s eye. De Barythinks that he is authorized in assuming the probability thatthe conceptacles and organs of fructification of others of theAscomycetes, including theDiscomycetes and theTuberacei, arethe results of sexual generation.

Certain phenomena which have been observed amongsttheConiomycetes are cited as examples of sexual association.Amongst these may be named the conjugation of the slenderspores of the first generation, produced on the germinating[178]threads ofTilletia,[O] and similar acts of conjugation, as observedin some species ofUstilago. Whether this interpretation shouldbe placed on those phenomena in the present condition of ourknowledge is perhaps an open question.

Fig. 101.—Tilletia caries with conjugating cells.

Finally, the spermogonia must be regarded as in some occultmanner, which as yet has baffled detection, influencing the perfectionof sporidia[P] InRhytisma,found on the leaves ofmaple and willow, black pitchyspots at first appear, whichcontain within them a goldenpulp, in which very slendercorpuscles are mixed with anabundant mucilage. Thesecorpuscles are the spermatia,which inRhytisma acerinumare linear and short, inRhytismasalicinum globose. Whenthe spermatia are expelled, thestroma thickens for the productionof asci and sporidia,which are afterwards developedduring the autumn and winter.

Several of the species ofHysterium also possess spermogonia,notablyH. Fraxini, which may be distinguished from the ascigerousperithecia with which they are associated by their smallersize and flask-like shape. From these the spermatia are expelledlong before the maturity of the spores. InHypoderma virgultorum,H. commune, andH. scirpinum, the spermogonia aresmall depressed black capsules, which contain an abundance ofminute spermatia. These were formerly regarded as distinctspecies, under the name ofLeptostroma. InStictis ocellata agreat number of the tubercles do not pass into the perfect state[179]until after they have produced either linear, very short spermatia,or stylospores, the latter being reproductive bodies of anoblong shape, equal in size to the perfect sporidia. Some ofthe tubercles never pass beyond this stage.

Again, there is a very common fungus which forms black discoidspots on dead holly leaves, calledCeuthospora phacidioides,figured by Greville in his “Scottish Cryptogamic Flora,” whichexpels a profusion of minute stylospores; but later in theseason, instead of these, we find the asci and sporidia ofPhacidiumilicis, so that the two are forms and conditions the one ofthe other.

InTympanis conspersa the spermogonia are much more commonlymet with than the complete fruit. There is a greatexternal resemblance in them to the ascigerous cups, but thereis no evidence that they are ever transformed into such. Theperfect sporidia are also very minute and numerous, beingcontained in asci borne in cups, which usually surround thespermogonia.

In several species ofDermatea the stylospores and spermatiaco-exist, but they are disseminated before the appearance of theascigerous receptacles, yet they are produced upon a commonstroma not unlike that ofTubercularia.

In its early stage the common and well-knownBulgariainquinans, which when mature looks like a blackPeziza, is alittle tubercle, the whole mass of which is divided into ramifiedlobes, the extremities of which become, towards the surface ofthe tubercle, receptacles from whence escape waves of spermatiawhich are colourless, or stylospores mixed with themwhich are larger and nearly black.

Amongst theSphæriacei numerous instances might be citedof minute stylosporous bodies in consort with, or preceding,the ascigerous receptacles. A very familiar example may befound at the base of old nettle stems in what has been namedAposphæria acuta, but which truly are only the stylospores oftheSphæria coniformis, the perithecia of which flourish in companyor in close proximity to them. Most of these bodies areso minute, delicate, and hyaline that the difficulties in the way[180]of tracing them in their relations to the bodies with which theyare associated are very great. Nevertheless there is strong presumptionin favour of regarding some of them as performingthe functions which the name applied to them indicates.

Professor de Bary cautiously refrains from accepting spermatiaother than as doubtful or at least uncertain sexual bodies.[Q] Hesays that the Messrs. Tulasne have supposed that the spermogoniarepresented the male sex, and that the spermatia wereanalogous to spermatozoids. Their opinion depends on twoplausible reasons,—the spermatia, in fact, do not germinate,and the development of the spermogonia generally precedesthe appearance of the sporophorous organs, a double circumstancewhich reminds us of what is known of the spermatozoidsand antheridia of other vegetables. It remained todiscover which were the female organs which underwentfecundation from the spermatia.

Many organs placed at first amongst spermatia have beenrecognized by M. Tulasne as being themselves susceptible ofgermination, and consequently ought to take their place amonglegitimate spores. Then it must be considered that very manyspores can only germinate under certain conditions. It is,therefore, for the present a doubtful question whether thereexist really any spermatia incapable of germination, or if thedefault of germination of these corpuscles does not ratherdepend on the experiments hitherto attempted not having includedthe conditions required by the phenomena. Moreover,as yet no trace has been discovered of the female organs whichare specially fecundated by the spermatia.

Finally, there exist in theAscomycetes certain organs ofreproduction, diverse spore-bearing apparatus, pycnidia, andothers, which, like the spermogonia, usually precede ascophorousfruits. The real nature of the spermogonia andspermatia should therefore be regarded as, at present, veryuncertain; as regards, however, the spermatia which havenever been seen to germinate, perhaps it is as well not toabsolutely reject the first opinion formed concerning them, or[181]perhaps they might be thought to perform the part of androspores,attributing to that expression the meaning whichPringsheim gives it in theConferoæ. The experiments performedwith the spermatia which do not germinate, and withthe spermogonia of the Uredines, do not, at any rate, appearto justify the reputed masculine or fecundative nature of theseorgans. The spermogonia constantly accompany or precedefruits ofÆcidium, whence naturally follows the presumptionthat the first are in a sexual relation to the second. Still,when Tulasne cultivatedEndophyllum sempervivum, he obtainedon some perfectly isolated rosettes ofSempervivum someÆcidiumrichly provided with normal and fertile spores, without any traceof spermogonia or of spermatia.

A great number of very interesting facts have during lateyears been brought to light of the different forms which fungiassume in the course of their development. At the same time,we fear that a great many assumptions have been accepted forfact, and supposed connections and relations between two orthree or more so-called species, belonging to different genera,have upon insufficient data been regarded as so many states orconditions of one and the same plant. Had the very pertinentsuggestions of Professor de Bary been more generally actedupon, these suspicions would have been baseless. His observationsare so valuable as a caution, that we cannot forbear prefacingour own remarks on this subject by quoting them.[A] In orderto determine, he says, whether an organic form, an organ, or anorganism, belongs to the same series of development as another,or that which is the same is developed from it, orvice versâ,there is only one way, viz., to observe how the second grows outof the first. We see the commencement of the second begin asa part of the first, perfect itself in connection with it, and atlast it often becomes independent; but be it through spontaneousdismembering from the first, or that the latter be destroyedand the second remains, both their disunited bodies are alwaysconnected together in organic continuity, as parts of a whole(single one) that can cease earlier or later.

By observing the organic continuity, we know that the appleis the product of development of an apple-tree, and not hung on[183]it by chance, that the pip of an apple is a product of the developmentof the apple, and that from the pip an apple-tree can at lastbe developed, that therewith all these bodies are members of asphere of development or form. It is the same with every similarexperience of our daily life, that where an apple-tree stands,many apples lie on the ground, or that in the place where apple-pipsare sown seedlings, little apple-trees, grow out of theground, is not important to our view of the course of development.Every one recognizes that in his daily life, because helaughs at a person who thinks a plum which lies under an apple-treehas grown on it, or that the weeds which appear among theapple seedlings come from apple-pips. If the apple-tree withits fruit and seed were microscopically small, it would not makethe difference of a hair’s breadth in the form of the question orthe method of answering it, as the size of the object canbe of no importance to the latter, and the questions which applyto microscopical fungi are to be treated in the same manner.

If it then be asserted that two or several forms belong to a seriesof development of one kind, it can only be based on the fact oftheir organic continuity. The proof is more difficult than in largeplants, partly because of the delicacy, minuteness, and fragilityof the single parts, particularly the greater part of the mycelia,partly because of the resemblance of the latter in differentspecies, and therefore follows the danger of confusing them withdifferent kinds, and finally, partly in consequence of the presenceof different kinds in the same substratum, and therefore themixture not only of different sorts of mycelia, but also thatdifferent kinds of spores are sown. With some care and patience,these difficulties are in no way insurmountable, and theymust at any rate be overcome; the organic continuity or non-continuitymust be cleared up, unless the question respecting thecourse of development, and the series of forms of special kinds,be laid on one side as insolvable.

Simple and intelligible as these principles are, they have notalways been acted upon, but partly neglected, partly expresslyrejected, not because they were considered false, but because thedifficulties of their application were looked upon as insurmountable.[184]Therefore another method of examination was adopted;the spores of a certain form were sown, and sooner or later theywere looked after to see what the seed had produced—not everysingle spore—but the seeden masse, that is, in other words,what had grown on that place where the seed had been sown.As far as it relates to those forms which are so widely spread,and above all grow in conjunction with one another—and thatis always the case in the specimens of which we speak—we cannever be sure that the spores of the form which we mean to testare not mingled with those of another species. He who hasmade an attentive and minute examination of this kind knowsthat we may be sure to find such a mixture, and that such anone was there can be afterwards decidedly proved. From theseed which is sown, these spores, for which the substratum wasmost suitable, will more easily germinate, and their developmentwill follow the more quickly. The favoured germs will suppressthe less favoured, and grow up at their expense. The samerelation exists between them as between the seeds, germs, andseedlings of a sown summer plant, and the seeds which havebeen undesignedly sown with it, only in a still more strikingmanner, in consequence of the relatively quick development ofthe mildew fungus.

Therefore, that from the latter a decided form, or a mixture ofseveral forms, is to be found sown on one spot, is no proof of theirgeneric connection with one which has been sown for the purposeof experiments; and the matter will only be more confused if wecall imagination to our aid, and place the forms which are foundnear one another, according to a real or fancied resemblance, in acertain series of development. All those statements on the sphereof form and connection, which have for their basis such a superficialwork, and are not based on the clear exposition of the continuityof development, as by the origin of the connection of theMucor withPenicillium,Oidium lactis andMucor,Oidium andPenicillium, are rejected as unfounded.

A source of error, which can also interfere in the last-namedsuperficial method of cultivation for experiments, is, viz., thatheterogeneous unwished-for spores intrude themselves from[185]without, among the seed which is sown, but that has beenuntil now quite disregarded. It is of great importance inpractice, but in truth, for our present purpose, synonymous withwhat we have already written. Those learned in the science ofthis kind of culture lay great stress on its importance, andmany apparatuses have been constructed, called “purely cultivatingmachines,” for the purpose of destroying the spores whichare contained in the substratum, and preventing the intrusion ofthose from without. The mixture in the seed which is sownhas of course not been obviated. These machines may, perhaps,in every other respect, fulfil their purpose, but they cannotchange the form of the question, and the most ingeniously constructedapparatus cannot replace the attention and intellect ofthe observer.[B]

Two distinct kinds of phenomena have been grouped underthe term “polymorphy.” In one series two or more forms offruit occur consecutively or simultaneously on the same individual,and in the other two or more forms appear on a differentmycelium, on a different part of the same plant, or on amatrix wholly distinct and different; in the latter case the connectionbeing attested or suspected circumstantially, in the formerproved by the method suggested by De Bary. It will at once beconceded that in cases where actual growth and developmentsubstantiate the facts the polymorphy is undoubted, whilst in theother series it can at best be little more than suspected. Wewill endeavour to illustrate both these series by examples.

One of the first and earliest suspected cases of dualism, whichlong puzzled the older mycologists, was observed amongst theUredines, and many years ago it was held that there must be somemysterious association between the “red rust” (Trichobasis ruligovera) of wheat and grasses and the “corn mildew” (Puccinia[186]graminis) which succeeded it. The simple spored rust firstmakes its appearance, and later the bilocular “mildew.” It isby no means uncommon to find the two forms in the same pustule.Some have held, without good reason, that the simplecells became afterwards divided and converted intoPuccinia,but this is not the case; the uredo-spores are always simple, andremain so except inUredo linearis, where every intermediatestage has been observed. Both are also perfect in their kind,and capable of germination.

What the precise relations between the two forms may be hasas yet never been revealed to observers, but that the two formsbelong to one species is not now doubted. Very many speciesofPuccinia have already been found associated with a correspondingTrichobasis, and ofPhragmidium with a relativeLecythea,but it may be open to grave doubt whether some of thevery many species associated by authors are not so classed uponsuspicion rather than observation. We are ready to admit thatthe evidence is strong in favour of the dimorphism of a largenumber of species—itmay be in all, but this awaits proof, orsubstantial presumption on good grounds. Up to the present weknow that there are species ofTrichobasis which have neverbeen traced to association with aPuccinia, and doubtless therewill be species ofPuccinia for which no correspondingUredoorTrichobasis can be found.

Tulasne remarks, in reference toPuccinia sonchi, in one of hismemoirs, that this curious species exhibits, in effect, that aPucciniamay unite three sorts of reproductive bodies, which, takingpart, constitute for the mycologists of the day three entirely differentplants—aTrichobasis, aUromyces, and aPuccinia. TheUredines are not less rich, he adds, in reproductive bodies ofdivers sorts than thePyrenomycetes and theDiscomycetes; andwe should not be surprised at this, since it seems to be a law,almost constant in the general harmony of nature, that thesmaller the organized beings are, the more their races areprolific.

InPuccinia variabilis, Grev., it is common to find a unicellularform, species ofTrichobasis, in the same pustules. A like circumstance[187]occurs withPuccinia violarum, Link., andTrichobasis violarum,B.; withPuccinia fallens, C., andTrichobasis fallens, Desm.;also withPuccinia menthæ, P., andTrichobasis Labiatarum, D. C.InMelampsora, again, the prismatic pseudospores ofMelampsorasalicina, Lev., are the winter fruits ofLecythea caprearum, Lev.,as those ofMelampsora populina, Lev., are ofLecythea populina,Lev. In the species ofLecythea themselves will be found, as DeBary[C] has shown, hyaline cysts of a larger size, which surroundthe pseudospores in the pustules in which they are developed.

A good illustration of dimorphism in one of the commonest ofmoulds is given by De Bary in a paper from which we havealready quoted.[D] He writes thus:—In every household there isa frequent unbidden guest, which appears particularly on preservedfruits, viz., themould which is calledAspergillus glaucus.It shows itself to the naked eye as a woolly floccy crust overthe substance, first purely white, then gradually covered withlittle fine glaucous, or dark green dusty heads. More minutemicroscopical examination shows that the fungus consists ofrichly ramified fine filaments, which are partly disseminated inthe substratum, and partly raised obliquely over it. They havea cylindrical form with rounded ends, and are divided into longoutstretched members, each of which possesses the propertywhich legitimatizes it as a vesicle in the ordinary sense of theword; it contains, enclosed within a delicate structureless wall,those bodies which bear the appearance of a finely granulatedmucous substance, which is designated by the name of protoplasm,and which either equally fills the cells, or the older thecell the more it is filled with watery cavities called vacuoles.

All parts are at first colourless. The increase in the lengthof the filaments takes place through the preponderating growthnear their points; these continually push forward, and, at ashort distance from them, successive new partitions rise up,but at a greater distance, the growth in the length ceases.This kind of growth is called point growth. The twigs and[188]branches spring up as lateral dilatations of the principal filament,which, once designed, enlarges according to the pointgrowth. This point growth of every branch is, to a certainextent, unlimited. The filaments in and on the substratum arethe first existing members of the fungus; they continue so longas it vegetates. As the parts which absorb nourishment from andconsume the substance, they are called themycelium. Nearlyevery fungus possesses a mycelium, which, without regard tothe specific difference of form and size, especially shows thedescribed nature in its construction and growth.

The superficial threads of the mycelium produce other filamentsbeside those numerous branches which have been described,and which are the fruit thread (carpophore) or conidia thread.These are on an average thicker than the mycelium threads, andonly exceptionally ramified or furnished with partitions; theyrise almost perpendicularly into the air, and attain a length of,on an average, half a millimetre, or one-fiftieth of an inch, butthey seldom become longer, and then their growth is at an end.Their free upper end swells in a rounded manner, and from thisis produced, on the whole of its upper part, rayed divergentprotuberances, which attain an oval form, and a length almostequal to their radius, or, in weaker specimens, the diameter ofthe rounded head. The rayed divergent protuberances are thedirect producers and bearers of the propagating cells, spores,or conidia, and are called sterigmata. Every sterigma at firstproduces at its point a little round protuberance, which, with astrong narrow basis, rests upon the sterigma. These are filledwith protoplasm, swell more and more, and, after some time,separate themselves by apartition from the sterigma into independentcells, spores, or conidia.

The formation of the first spore takes place at the same endof the sterigma, and in the same manner a second follows, thena third, and so on; every one which springs up later pushesits predecessor in the direction of the axis of the sterigma inthe same degree in which it grows itself; every successive sporeformed from a sterigma remains for a time in a row with oneanother. Consequently every sterigma bears on its apex a chain[189]of spores, which are so much the older, the farther they standfrom the sterigma. The number of the links in a chain of sporesreaches in normal specimens to ten or more. All sterigmataspring up at the same time, and keep pace with one anotherin the formation of the spores. Every spore grows for a time,according to its construction, and at last separates itself fromits neighbours. The mass of dismembered spores forms thatfine glaucous hue which is mentioned above. The spores, therefore,are articulated in rows, one after the other, from the endsof the sterigmata. The ripe spore, or conidium, is a cell of around or broadly oval form, filled with a colourless protoplasm,[190]and, if observed separately, is found to be provided with abrownish, finely verruculose, dotted wall.

Fig. 102.—a.Aspergillus glaucus;b. conidia;c. germinating conidium;d. conceptacle ofEurotium;e. ascus.

The same mycelium which forms the pedicel for the conidiawhen it is near the end of its development, forms by normalvegetation a second kind of fructification. It begins as delicatethin little branches, which are not to be distinguished by thenaked eye, and which mostly in four or six turns, after a quicklyterminated growth, wind their ends like a corkscrew. (Fig. 102.)The sinuations decrease in width more and more, till they at lastreach close to one another, and the whole end changes from theform of a corkscrew into that of a hollow screw. In and onthat screw-like body, a change of a complicated kind takes place,which is a productive process. In consequence of this, from thescrew body a globose receptacle is formed, consisting of a thinwall of delicate cells, and a closely entwined row of cells surroundedby this dense mass (d). By the enlargement of all theseparts the round body grows so much, that by the time it is ripeit is visible to the naked eye. The outer surface of the wallassumes a compactness and a bright yellow colour; the greaterpart of the cells of the inner mass become asci for the formationof sporidia, while they free themselves from the reciprocal union,take a broad oval form, and each one produces within its innerspace eight sporidia (e). These soon entirely fill the ascus.When they are quite ripe, the wall of the conceptacle becomesbrittle, and from irregular fissures, arising easily from contact,the colourless round sporidia are liberated.

The pedicels of both kinds of fruit are formed from the samemycelium in the order just described. If we examine attentively,we can often see both springing up close to one another from thesame filament of a mycelium. This is not very easy in the closeinterlacing of the stalks of a mass of fungi in consequence oftheir delicacy and fragility. Before their connection was known,the conceptacles and the conidia pedicels were considered asorgans of two very different species of fungi. The conceptacleswere calledEurotium herbariorum, and the conidia bearers werecalledAspergillus glaucus.

Fig. 103.—Erysiphe cichoracearum.a. Receptacle;o. mycelium. (De Bary.)

Allied toEurotium is the group ofErysiphei, in which well-authenticated[191]polymorphy prevails. These fungi are developedon the green parts of growing plants, and at first consist of awhite mouldy stratum, composed of delicate mycelium, on whicherect threads are produced, which break up into subglobosejoints or conidia. The species on grass was namedOidiummonilioides before its relationship was known, but undoubtedlythis is only the conidia ofErysiphe graminis. In like mannerthe vine disease (Oidium Tuckeri) is most probably only theconidia of a species ofErysiphe, of which the perfect conditionhas not yet been discovered. On roses the oldOidium leucoconiumis but the conidia ofSphærotheca pannosa, and soof other species. TheErysiphe which ultimately appears onthe same mycelium consists of globose perithecia, externallyfurnished with thread-like appendages, and internally with ascicontaining sporidia. In this genus there are no less than fivedifferent forms of fruit,[E] the multiform threads on the mycelium,already alluded to as forms ofOidium, the asci contained inthe sporangia, which is the proper fruit of theErysiphe, largerstylospores which are produced in other sporangia, the smallerstylospores which are generated in the pycnidia, and separatesporules which are sometimes formed in the joints of the necklacesof the conidia. These forms are figured in the “Introduction[192]to Cryptogamic Botany” fromSphærotheca Castagnei, which isthe hop mildew.[F] The vine disease, hop mildew, and rosemildew, are the most destructive species of this group, and theconstant annoyance of cultivators.

When first describing an allied fungus found on old paper, andnamedAscotricha chartarum, the Rev. M. J. Berkeley called attentionto the presence of globose conidia attached to the threadswhich surround the conceptacles,[G] and this occurred as longsince as 1838. In a recent species ofChætomium found on oldsacking,Chætomium griseum, Cooke,[H] we have found tufts in allrespects similar externally to theChætomium, but no peritheciumwas formed, naked conidia being developed apparently at thebase of the coloured threads. InChætomium funicolum, Cooke,a black mould was also found which may possibly prove to beits conidia, but at present there is no direct evidence.

The brothers Tulasne have made us acquainted with a greaternumber of instances amongst theSphæriacei in which multipleorgans of reproduction prevail. Very often old and decayingindividuals belonging to species ofBoletus will be found filled,and their entire substance internally replaced, by the threads andmultitudinous spores of a golden yellow parasite, to which thename ofSepedonium chrysospermum has been given. Accordingto Tulasne, this is merely a condition of a sphæriaceous fungusbelonging to his genusHypomyces.[I]

The same observers also first demonstrated thatTrichodermaviride, P., was but the conidia-bearing stage ofHypocrea rufa,P., another sphæriaceous fungus. The ascigerous stroma of thelatter is indeed frequently associated in a very close manner withthe cushions of the pretendedTrichoderma, or in other cases thesame stroma will give rise to a different apparatus of conidia,of which the principal elements are acicular filaments, which areshort, upright, and almost simple, and which give rise to small[193]oval conidia which are solitary on the tips of the threads.Therefore thisHypocrea will possess two different kinds ofconidia, as is the case in many species ofHypomyces.

A most familiar instance of dualism will be found inNectriacinnabarina, of which the conidia form is one of the most commonof fungi, forming little reddish nodules on all kinds of deadtwigs.[J]

Fig. 104.—Twig withTubercularia on the upper portion,Nectria on the lower.

Almost any small currant twig which has been lying on theground in a damp situation will afford an opportunity of studyingthis phenomenon. The whole surface of the twig will be coveredfrom end to end with little bright pink prominences, burstingthrough the bark at regular distances, scarcely a quarter of aninch apart. Towards one end of the twig probably the prominenceswill be of a deeper, richer colour, likepowdered cinnabar. The naked eye is sufficientto detect some difference between the two kindsof pustules, and where the two merge into eachother specks of cinnabar will be visible on thepink projections. By removing the bark it willbe seen that the pink bodies have a sort ofpaler stem, which spreads above into a somewhatglobose head, covered with a delicate mealy bloom.At the base it penetrates to the inner bark, andfrom it the threads of mycelium branch in alldirections, confined, however, to the bark, andnot entering the woody tissues beneath. Thehead, placed under examination, will be found toconsist of delicate parallel threads compacted togetherto form the stem and head. Some of thesethreads are simple, others are branched, bearinghere and there upon them delicate little bodies,which are readily detached, and which form themealy bloom which covers the surface. These are the conidia,little slender cylindrical bodies, rounded at the ends.

Passing to the other bodies, which are of a deeper colour, it[194]will soon be discovered that, instead of being simple roundedheads, each tubercle is composed of numerous smaller, nearlyglobose bodies, closely packed together, often compressed, allunited to a base closely resembling the base of the othertubercles. If for a moment we look at one of the tubercles nearthe spot where the crimson tubercles seem to merge into thepink, we shall not only find them particoloured, but that the redpoints are the identical globose little heads just observed inclusters. This will lead to the suspicion, which can afterwardsbe verified, that the red heads are really produced on the stemor stroma of the pink tubercles.

Fig. 105.—Section ofTubercularia.c. Threads with conidia.[K]

A section of one of the red tubercles will show us how muchthe internal structure differs. The little subglobose bodieswhich spring from a common stroma or stem are hollow shellsor capsules, externally granular, internally filled with a gelatinousnucleus. They are, indeed, the perithecia of a sphæriaceousfungus of the genusNectria, and the gelatinous nucleus containsthe fructification. Still further examination will show that thisfructification consists of cylindrical asci, each enclosing eightelliptical sporidia, closely packed together, and mixed withslender threads called paraphyses.

Here, then, we have undoubted evidence ofNectria cinnabarina,with its fruit, produced in asci growing from the stromaor stem, and in intimate relationship with what was formerlynamedTubercularia vulgaris. A fungus with two forms of fruit,[195]one proper to the pink, orTubercularia form, with naked slenderconidia, the other proper to the mature fungus, enclosed in asci,and generated within the walls of a perithecium. Instances ofthis kind are now known to be far from uncommon, althoughthey cannot always, or often, be so clearly and distinctly tracedas in the illustration which we have selected.

Fig. 106.—D.Nectria surroundingTubercularia; E. tuft ofNectria cinnabarina; F. section of stroma; G. ascus and paraphyses.

It is not uncommon for the conidia of theSphæria to partakeof the characteristics of a mould, and then the perithecia aredeveloped amongst the conidial threads. A recently recordedinstance of this relates toSphæria Epochnii, B. and Br.,[L] theconidia form of which was long known before theSphæriarelated to it was discovered, under the name ofEpochniumfungorum. TheEpochnium forms a thin stratum, which overrunsvarious species ofCorticium. The conidia are at first uniseptate.The perithecia of theSphæria are at first pale bottle-green,crowded in the centre of theEpochnium, then black greengranulated, sometimes depressed at the summit, with a minutepore. The sporidia are strongly constricted in the centre, atfirst uniseptate, with two nuclei in each division.

AnotherSphæria in which the association is undoubted is the[196]Sphæria aquila, Fr.,[M] which is almost always found nestling in awoolly brown subiculum, for the most part composed of barrenbrown jointed threads. These threads, however, produce, underfavourable conditions, mostly before the perfection of the perithecia,minute subglobose conidia, and in this state constitutewhat formerly bore the name ofSporotrichum fuscum, Link., butnow recognized as the conidia ofSphæria aquila.

InSphæria nidulans, Schw., a North American species, we havemore than once found the dark brown subiculum bearing largetriseptate conidia, having all the characters of the genusHelminthosporium.InSphæria pilosa, P., Messrs. Berkeley and Broomehave observed oblong conidia, rather irregular in outline, terminatingthe hairs of the perithecium.[N] The same authorshave also figured the curious pentagonal conidia springing fromflexuous threads accompanyingSphæria felina, Fckl.,[O] and alsothe threads resembling those of aCladotrichum with the angularconidia ofSphæria cupulifera, B. and Br.[P] A most remarkableexample is also given by the Brothers Tulasne inPleosporapolytricha, in which the conidia-bearing threads not onlysurround, but grow upon the perithecia, and are crowned byfascicles of septate conidia.[Q]

Instances of this kind have now become so numerous thatonly a few can be cited as examples of the rest. It is not at allimprobable that the majority of what are now classed togetheras species under the genus of black moulds,Helminthosporium,will at some not very distant period be traced as the conidia ofdifferent species of ascomycetous fungi. The same fate mayalso await other allied genera, but until this association isestablished, they must keep the rank and position which hasbeen assigned to them.

Another form of dualism, differing somewhat in character[197]from the foregoing, finds illustration in the sphæriaceous genusMelanconis, of Tulasne, in which the free spores are still calledconidia, though in most instances produced in a sort of spuriousconceptaculum, or borne on short threads from a kind ofcushion-shaped stroma. In theMelanconis stilbostoma,[R] thereare three forms, one of slender minute bodies, oozing out in theform of yellow tendrils, which may be spermatia, formerly calledNemaspora crocea. Then there are the oval brown or olive brownconidia, which are at first covered, then oozing out in a blackpasty mass, formerlyMelanconium bicolor, and finally the sporidiain asci ofSphæria stilbostoma, Fries. InMelanconis Berkeleii,Tul., the conidia are quadrilocular, previously known asStilbosporamacrosperma, B. and Br. In a closely-allied species fromNorth America,Melanconis bicornis, Cooke, the appendiculatesporidia are similar, and the conidia would also appear to partakeof the character ofStilbospora. We may remark here that wehave seen a brown mould, probably an undescribed species ofDematiei, growing in definite patches around the openings inbirch bark caused by the crumpent ostiola of the perithecia ofMelanconis stilbostoma, from the United States.

InMelanconis lanciformis,[S] Tul., there are, it would appear,four forms of fruit. One of these consists of conidia, characterizedby Corda asCoryneum disciforme.[T] Stylospores, whichare also figured by Corda under the name ofConiothecium betulinum;pycnidia,[U] first discovered by Berkeley and Broome, andnamed by themHendersonia polycystis;[V] and the ascophorousfruits which constituted theSphæria lanciformis of Fries. Mr.Currey indicatedHendersonia polycystis, B. and Br., as a formof fruit of this species in a communication to the Royal Societyin 1857.[W] He says this plant grows upon birch, and is in perfectionin very moist weather, when it may be recognized by the[198]large black soft gelatinous protuberances on the bark, formedby spores escaping and depositing themselves upon and aboutthe apex of the perithecium. This I suspect to be an abnormalstate of a well-known Sphæria (S. lanciformis), which growsupon birch, and upon birch only.

We might multiply, almost indefinitely, instances amongst theSphæriacei, but have already given sufficient for illustration, andwill therefore proceed briefly to notice some instances amongsttheDiscomycetes, which also bear their complete or perfect fruitin asci.

The beautiful purple stipitate cups ofBulgaria sarcoides,which may be seen flourishing in the autumn on old rottenwood, are often accompanied by club-shaped bodies of the samecolour; or earlier in the season these clavate bodies may befound alone, and at one time bore the name ofTremellasarcoides. The upper part of these clubs disseminate a greatabundance of straight and very slender spermatia. Earlier thanthis they are covered with globose conidia. The fully-maturedBulgaria develops on its hymenium clavate delicate asci, eachenclosing eight elongated hyaline sporidia, so that we have threeforms of fruit belonging to the same fungus, viz. conidia andspermatia in theTremella stage, and sporidia contained in asciin the mature condition.[X] The same phenomena occur withBulgaria purpurea, a larger species with different fruit, longconfounded withBulgaria sarcoides.

On the dead stems of nettles it is very common to meet withsmall orange tubercles, not much larger than a pin’s head,which yield at this stage a profusion of slender linear bodies,produced on delicate branched threads, and at one time bore thename ofDacrymyces Urticæ, but which are now acknowledged tobe only a condition of a little tremelloidPeziza of the same sizeand colour, which might be mistaken for it, if not examinedwith the microscope, but in which there are distinct asci andsporidia. Both forms together are now regarded as the samefungus, under the name ofPeziza fusarioides, B.

The other series of phenomena grouped together under thename of polymorphism relate to forms which are removed fromeach other, so that the mycelium is not identical, or, moreusually, produced on different plants. The first instance of thiskind to which we shall make reference is one of particularinterest, as illustrative of the old popular creed, that berberrybushes near corn-fields produced mildewed corn. There is avillage in Norfolk, not far from Great Yarmouth, called “MildewRollesby,” because of its unenviable notoriety in days pastfor mildewed corn, produced, it was said, by the berberrybushes, which were cut down, and then mildew disappearedfrom the corn-fields, so that Rollesby no longer merited itssobriquet. It has already been shown that the corn-mildew(Puccinia graminis) is dimorphous, having a one-celled fruit(Trichobasis), as well as a two-celled fruit (Puccinia). Thefungus which attacks the berberry is a species of cluster-cup(Æcidium berberidis), in which little cup-like peridia, containingbright orange pseudospores, are produced in tufts or clusters onthe green leaves, together with their spermogonia.

De Bary’s observations on this association of forms were publishedin 1865.[Y] In view of the popular belief, he determinedto sow the spores ofPuccinia graminis on the leaves of the berberry.For this purpose he selected the septate resting spores fromPoa pratensis andTriticum repens. Having caused the spores togerminate in a moist atmosphere, he placed fragments of theleaves on which they had developed their secondary spores onyoung but full-grown berberry leaves, under the same atmosphericconditions. In from twenty-four to forty-eight hoursa quantity of the germinating threads had bored through thewalls and penetrated amongst the subjacent cells. This tookplace both on the upper and under surface of the leaves. Since,in former experiments, it appeared that the spores wouldpenetrate only in those cases where the plant was adapted todevelop the parasite, the connection betweenP. graminis and[200]Æcid. berberidis seemed more than ever probable. In about tendays the spermogonia appeared. After a time the cut leavesbegan to decay, so that the fungus never got beyond thespermogonoid stage. Some three-year-old seedlings were thentaken, and the germinating resting spores applied as before.The plants were kept under a bell-glass from twenty-four toforty-eight hours, and then exposed to the air like other plants.From the sixth to the tenth day, yellow spots appeared, withsingle spermogonia; from the ninth to the twelfth, spermogoniaappeared in numbers on either surface; and, a few days later,on the under surface of the leaves, the cylindrical sporangiaof theÆcidium made their appearance, exactly as in thenormally developed parasite, except that they were longer,from being protected from external agents. The younger theleaves, the more rapid was the development of the parasite, andsometimes, in the younger leaves, the luxuriance was far greaterthan in free nature. Similar plants, to the number of twohundred, were observed in the nursery, and though some of themhadÆcidium pustules, not one fresh pustule was produced;while two placed under similar circumstances, but without theapplication of any resting spores, remained all the summer freefromÆcidium. It seems, then, indubitable so far thatÆcidiumberberidis does spring from the spores ofPuccinia graminis.

It has, however, to be remarked that De Bary was not equallysuccessful in producing thePuccinia from the spores of theÆcidium. In many cases the spores do not germinate whenplaced on glass, and they do not preserve their power of germinatingvery long. He reverts then to the evidence of experimentsinstituted by agriculturists. Bönninghausen remarked, in1818, that wheat, rye, and barley which were sown in the neighbourhoodof a berberry bush covered withÆcidium contractedrust immediately after the maturation of the spores of theÆcidia.The rust was most abundant where the wind carried the spores.The following year the same observations were repeated; thespores of theÆcidium were collected, and applied to some healthyplants of rye. After five or six days these plants were affectedwith rust, while the remainder of the crop was sound. In 1863[201]some winter rye was sown round a berberry bush, which in thefollowing year was infested withÆcidium, which was mature inthe middle of May, when the rye was completely covered withrust. Of the wild grasses near the bush,Triticum repens wasmost affected. The distant plants of rye were free from rust.

Fig. 107.—Cells and pseudospores ofÆcidium berberidis.

The spores of theÆcidium would not germinate on berberryleaves; the berberryÆcidium could not therefore spring fromthe previousÆcidium. The uredospores ofPuccinia graminison germinating penetrate into the parenchym of the grass onwhich they are sown; but on berberry leaves, if the tips of thethreads enter for a short distance into the stomates their growthat once ceases, and the leaves remain free from parasites.

Fig. 108.—Cells and pseudospores ofÆcidium graveolens.

Montagne has, however, described aPuccinia berberidis onleaves ofBerberis glauca from Chili, which grows in companywithÆcidium berberidis. This at first sight seems to contradictthe above conclusions; but theÆcidium which from the samedisc produces the puccinoid resting spores, appears to be differentfrom the European species, inasmuch as the cells of thewall of the sporangium are twice as large, and the spores decidedlyof greater diameter.[Z] The resting spores, moreover,[202]differ not only from those ofPuccinia graminis, but from thoseof all other European species.

From this account, then, it is extremely probable that theÆcidium of the berberry enters into the cycle of existence ofPuccinia graminis, and, if this be true, wherefore should notother species ofPuccinia be related in like manner to otherÆcidia? This is the conclusion to which many have arrived,and, taking advantage of certain presumptions, have, we fear,rashly associated many such forms together without substantialevidence. On the leaves of the primrose we have commonly aspecies ofÆcidium,Puccinia, andUromyces nearly at the sametime; we may imagine that all these belong to one cycle, butit has not yet been proved. Again,Uromyces cacaliæ, Unger,Uredo cacaliæ, Unger, andÆcidium cacaliæ, Thumen, are consideredby Heufler[a] to form one cycle. Numerous others aregiven by Fuckel,[b] and De Bary, in the same memoir from whichwe have already cited, notesUromyces appendiculatus, Link.,U. phaseolorum, Tul., andPuccinia tragopogonis, Ca., as possessingfive kinds of reproductive organs. Towards the end of the year,shortly stipitate spores appear on their stroma, which do not falloff. These spores, which do not germinate till after a shorter orlonger winter rest, may conveniently be called resting spores, or,as De Bary calls them,teleutospores, being the last which areproduced. These at length germinate, become articulated, andproduce ovate or kidney-shaped spores, which in their turngerminate, penetrating the cuticle of the mother plant, avoidingthe stomates or apertures by which it breathes. After abouttwo or three weeks, the mycelium, which has ramified among the[203]tissues, produces anÆcidium, with its constant companion, spermogonia—distinctcysts, that is, from which a quantity of minutebodies ooze out, often in the form of a tendril, the function ofwhich is imperfectly known at present, but which from analogywe regard as a form of fruit, though it is just possible that theymay be rather of the nature of spermatozoids. TheÆcidiacontain, within a cellular membranous sac, a fructifying disc,which produces necklaces of spores, which ultimately separatefrom each other in the form of a granular powder. The grainsof which it is composed germinate in their turn, no longeravoiding the stomates as before, but penetrating through theiraperture into the parenchym. The new resultant myceliumreproduces theUredo, or fifth form of fructification, and theUredo spores fall off like those of theÆcidium, and in respectof germination, and mode of penetration, present precisely thesame phenomena. The disc which has produced theUredospores now gives rise to the resting spores, and so the cycle iscomplete.[c]

The late Professor Œrsted, of Copenhagen, was of opinionthat he had demonstrated the polymorphy of the TremelloidUredines, and satisfied himself that the one condition known asPodisoma was but another stage ofRœstelia.[d] Some freshlygathered specimens ofGymnosporangium were damped withwater, and during the night following the spores germinatedprofusely, so that the teleutospores formed an orange-colouredpowder. A little of this powder was placed on the leaves offive small sorbs, which were damped and placed under bell-glasses.In five days yellow spots were seen on the leaves, andin two days more indications of spermogonia. The spermatiawere discharged, and in two months from the first sowing,[204]the peridia ofRœstelia appeared, and were developed. “Thistrial of spores,” says Œrsted, “has conduced to the result expected,and proves that the teleutospores ofGymnosporangium,when transported upon the sorb, give rise to a totally differentfungus, theRœstelia cornuta, that is to say, that an alternategeneration comes between these fungi. They appertain in consequenceto a single species, and theGymnosporangium ceased tobe an independent species, and must be considered as synonymouswith the first generation ofRœstelia. The spores havebeen transported upon young shoots of the juniper-tree, andhave now commenced to produce some mycelium in the bark.There is no doubt that in next spring it will result inGymnosporangium.”

Subsequently the same learned professor instituted similarexperiments upon other hosts, with the spores ofPodisoma, andfrom thence he concluded thatRœstelia andPodisoma, in alltheir known species, were but forms the one of the other.Hitherto we are not aware that these results have been confirmed,or that the sowing of the spores ofRœstelia on juniperresulted inPodisoma. Such experiments should be receivedalways with care, and not too hastily accepted in their apparentresults as proven facts. Who shall say thatRœstelia would nothave appeared onSorbus within two months without the sowingofPodisoma spores?—because it is not by any means uncommonfor that fungus to appear upon that plant. It is true manymycologists write and speak ofRœstelia andPodisoma (orGymnosporangium) as identical; but, as we think, without theevidence being so complete as to be beyond suspicion. It is,nevertheless, a curious fact that in Europe the number of speciesofRœstelia andPodisoma are equal, if one species be excluded,which is certainly not a goodPodisoma, for the reception ofwhich a new genus has been proposed.[e]

Amongst the ascigerous fungi will be found a curious but interestinggenus formerly calledCordyceps, but for which Tulasne,in consequence of the discovery of secondary forms of fruit,[205]has substituted that ofTorrubia.[f] These curious fungi partakemore or less of a clavate form, and are parasitic on insects.The pupæ of moths are sometimes seen bearing upon them thewhite branched mould, something like aClavaria in appearance,to which the name ofIsaria farinosa has been given. Accordingto Tulasne, this is the conidia form of the bright scarlet, club-shapedbody which is also found on dead pupæ, calledTorrubiamilitaris. An American mould of the same genus,Isariasphingum, found on mature moths,[g] is in like manner declared tobe the conidia ofTorrubia sphingum; whereas a similar mould,found on dead spiders, calledIsaria arachnophila,[h] is probablyof a similar nature. An allied kind of compact mould, whichis parasitic onCocci, on the bark of trees, recently found inEngland by Mr. C. E. Broome, and namedMicrocera coccophila,[i]is said by Tulasne to be a condition ofSphærostilbe, and it isintimated that other productions of a similar character bearlike relations to othersphæriaceous fungi. For many speciesofTorrubia no corresponding conidia are yet known.

Some instances might be noted, not without interest, inwhich the facts of dimorphism or polymorphism have not beensatisfactorily proved, but final judgment is held in suspenseuntil suspicion is replaced by conviction. Some years since, aquantity of dead box leaves were collected, on which flourished atthe time a mould namedPenicillium roseum. This mould has aroseate tint, and occurs in patches on the dead leaves lying uponthe ground; the threads are erect and branched above, bearingchains of oblong, somewhat spindle-shaped spores, or, perhapsmore accurately, conidia. When collected, these leaves wereexamined, and nothing was observed or noted upon them exceptthisPenicillium. After some time, certainly between two andthree years, during which period the box remained undisturbed,circumstances led to the examination again of one or two of theleaves, and afterwards of the greater number of them, when the[206]patches ofPenicillium were found to be intermixed with anothermould of a higher development, and far different character.This mould, or ratherMucor, consists of erect branchingthreads, many of the branches terminating in a delicate globose,glassy head, or sporangium, containing numerous very minutesubglobose sporidia. This species was namedMucor hyalinus.[j]The habit is very much like that of thePenicillium, but withoutany roseate tint. It is almost certain that theMucor could nothave been present when thePenicillium was examined, and theleaves on which it had grown were enclosed in the tin box, butthat theMucor afterwards appeared on the same leaves, sometimesfrom the same patches, and, as it would appear, from thesame mycelium. The great difference in the two species lies inthe fructification. In thePenicillium, the spores are naked, andin moniliform threads; whilst inMucor the spores are enclosedwithin globose membraneous heads or sporangia. Scarcely canwe doubt that theMucor alluded to above, found thus intermixed,under peculiar circumstances, withPenicillium roseum, is no otherthan the higher and more complete form of that species, andthat thePenicillium is only its conidiiferous state. The presumptionin this case is strong, and not so open to suspicion as itwould be did not analogy render it so extremely probable thatsuch is the case, apart from the fact of both forms springingfrom the same mass of mycelium. In such minute and delicatestructures it is very difficult to manipulate the specimens so asto arrive at positive evidence. If a filament of mycelium couldbe isolated successfully, and a fertile thread, bearing the fruit ofeach form, could be traced from the same individual myceliumthread, the evidence would be conclusive. In default of suchconclusive evidence, we are compelled to rest with assumptionuntil further researches enable us to record the assumption asfact.[k]

Apropos of this very connection ofPenicillium withMucor, asimilar suspicion attaches to an instance noted by a wholly disinterested[207]observer to this effect. “On a preparation preservedin a moist chamber, on the third day a white speck was seen onthe surface, consisting of innumerable ‘yeast’ cells, with somefilaments, branching in all directions. On the fourth day tuftsofPenicillium, had developed two varieties—P. glaucum andP. viride. This continued until the ninth day, when a few ofthe filaments springing up in the midst of thePenicillium weretipped with a dewdrop-like dilatation, excessively delicate—amere distended pellicle. In some cases they seemed to bederived from the same filament as others bearing the ordinarybranching spores ofPenicillium, but of this I could not bepositive. This kind of fructification increased rapidly, and onthe fourteenth day spores had undoubtedly developed within thepellicle, just as had been observed in a previous cultivation,precisely similar revolving movements being also manifested.”[l]Although we have here another instance ofMucor andPenicilliumgrowing in contact, the evidence is insufficient to warrant morethan a suspicion of their identity, inasmuch as the equallyminute spores ofMucor andPenicillium might have mingled,and each producing its kind, no relationship whatever haveexisted between them, except their development from the samematrix.

Another case of association—for the evidence does not proceedfurther—was recorded by us, in which a dark-coloured speciesofPenicillium was closely associated with what we now believeto be a species ofMacrosporium—but then designated aSporidesmium—anda minuteSphæria growing in succession ondamp wall-paper. Association is all that thefacts warrant usin calling it.

We cannot forbear alluding to one of the species ofSphæriato which Tulasne[m] attributes a variety of forms of fruit, and wedo so here because we think that a circumstance so extraordinaryshould be confirmed before it is accepted as absolutely true.This refers to the commonSphæria found on herbaceous plants,[208]known asSphæria (Pleospora)herbarum. First of all the verycommon mould calledCladosporium herbarum is constituted asconidia, and of this againMacrosporium sarcinula, Berk., is consideredto be another condition. In the next place,Cytisporaorbicularis, Berk., andPhoma herbarum, West., are regarded aspycnidia, enclosing stylospores. ThenAlternaria tenuis, Pr.,[n]which is said to be parasitic onCladosporium herbarum, is heldto be only a form of that species, so that here we have (includingtheperithecia) no less than six forms or phases for the samefungus. AsMacrosporium Cheiranthi, Pr., often is found incompany withCladosporium herbarum, that is also open tosuspicion.

We have adduced in the foregoing pages a few instanceswhich will serve to illustrate the polymorphism of fungi.Some of these it will be observed are accepted as beyond doubt,occurring as they do in intimate relationship with each other.Others are considered as scarcely so well established, butprobable, although developed sometimes on different species ofplants. Finally, some are regarded as hitherto not satisfactorilyproved, or, it may be, only suspicious. In this latter group,however much probability may be in their favour, it can hardlybe deemed philosophical to accept them on such slender evidenceas in some cases alone is afforded. It would not have beendifficult to have extended the latter group considerably by theaddition of instances enumerated by various mycologists intheir works without any explanation of the data upon whichtheir conclusions have been founded. In fact, altogether thischapter must be accepted as illustrative and suggestive, but byno means as exhaustive.

It is no longer doubted that fungi exercise a large and veryimportant influence in the economy of nature. It may be thatin some directions these influences are exaggerated; but it iscertain that on the whole their influence is far more importantfor evil and for good than that of any other of the Cryptogamia.In our endeavour to estimate the character and extent of theseinfluences it will prove advantageous to examine them underthree sections. 1. Their influence on man. 2. Their influenceon lower animals. 3. Their influence on vegetation. Underthese sections the chief facts may be grouped, and some approximateidea obtained of the very great importance of this family ofinferior plants, and consequently the advisability of pursuingtheir study more thoroughly and nationally than has hithertobeen done.

I. In estimating the influence of fungi upon man, we naturallyenough seek in the first instance to know what baneful effectsthey are capable of producing on food. Although in the case of“poisonous fungi,” popularly understood, fungi may be thepassive agents, yet they cannot be ignored in an inquiry of thisnature. Writing of the Uses of Fungi, we have already shownthat a large number are available for food, and some of thesereal delicacies; so, on the other hand, it becomes imperative,even with stronger emphasis, to declare that many are poisonous,and some of them virulently so. It is not sufficient to say thatthey are perfectly harmless until voluntarily introduced into thehuman system, whilst it is well known that accidents are always[210]possible, and probably would be if every baneful fungus had theword POISON inscribed in capitals on its pileus.

The inquiry is constantly being made as to what plain rulescan be given for distinguishing poisonous from edible fungi, andwe can answer only that there are none other than those whichapply to flowering plants. How can aconite, henbane, œnanthe,stramonium, and such plants, be distinguished from parsley,sorrel, watercress, or spinach? Manifestly not by any generalcharacters, but by specific differences. And so it is with thefungi. We must learn to discriminateAgaricus muscarius fromAgaricus rubescens, in the same manner as we would discriminateparsley fromÆthusa cynapium. Indeed, fungi have an advantagein this respect, since one or two general cautions can be given,when none such are applicable for higher plants. For instance,it may be said truly that all fungi that exhibit a rapid changeto blue when bruised or broken should be avoided; that allAgarics are open to suspicion which possess an acrid taste; thatfungi found growing on wood should not be eaten unless thespecies is well known; that no species of edible fungus has astrong, unpleasant odour, and similar cautions, which, after all,are insufficient. The only safe guide lies in mastering, one byone, the specific distinctions, and increasing the number of one’sown esculents gradually, by dint of knowledge and experience,even as a child learns to distinguish a filbert from an acorn, orwith wider experience will thrust in his mouth a leaf ofOxalisand reject that of the white clover.

One of the most deleterious of fungi that we possess is at thesame time one of the most beautiful. This is theAgaricusmuscarius, or Fly Agaric, which is sometimes used as a flypoison.[A] It has a bright crimson pileus studded with palewhitish (sometimes yellowish) warts, and a stem and gills ofivory whiteness. Many instances have been recorded of poisoningby this fungus, and amongst them some British soldiersabroad, and yet it cannot be doubted that this fungus is eaten in[211]Russia. Two instances have come under our notice of personswith some botanical knowledge, and one a gardener, who hadresided in Russia and eaten of this fungus. In one case the FlyAgaric was collected and shown to us, and in the other thefigure was indicated, so that we might be under no doubt as tothe species. Only one hypothesis can be advanced in explanation.It is known that a large number of fungi are eaten inRussia, and that they enter much into the domestic cookery ofthe peasantry, but it is also known that they pay considerableattention to the mode of cooking, and add a large amount of saltand vinegar, both of which, with long boiling, must be powerfulagents in counteracting the poison (probably somewhat volatile)of such fungi as the Fly Agaric. In this place we may give arecipe published by a French author of a process for renderingpoisonous fungi edible. It must be taken on his authority, andnot our own, as we have never made the experiment, notwithstandingit seems somewhat feasible:—For each pound of mushrooms,cut into moderately small pieces, take a quart of wateracidulated with two or three spoonfuls of vinegar, or two spoonfulsof bay salt. Leave the mushrooms to macerate in the liquidfor two hours, then wash them with plenty of water; this done,put them in cold water and make them boil. After a quarter orhalf hour’s boiling take them off and wash them, then drain, andprepare them either as a special dish, or use them for seasoningin the same manner as other species.[B]

This method is said to have been tried successfully with someof the most dangerous kinds. Of these may be mentioned theemetic mushroom,Russula emetica, with a bright red pileus and[212]white gills, which has a clear, waxy, tempting appearance, butwhich is so virulent that a small portion is sufficient to producedisagreeable consequences. It would be safer to eschew all fungiwith a red or crimson pileus than to run the risk of indulging inthis. A white species, which, however, is not very common,with a bulbous base enclosed in a volva, calledAgaricus vernus,should also be avoided. The pink spored species should also beregarded with suspicion. Of theBoleti several turn blue whencut or broken, and these again require to be discarded. This isespecially the case withBoletus luridus[C] andBoletus Satanas,[D]two species which have the under surface or orifice of the poresof a vermilion or blood-red colour.

Not only are species which are known to be poisonous to beavoided, but discretion should be used in eating recognized goodspecies. Fungi undergo chemical changes so rapidly that eventhe cultivated mushroom may cause inconvenience if kept solong after being gathered as to undergo chemical change. It isnot enough that they should be of a good kind, but also fresh.The employment of plenty of salt in their preparation is calculatedvery much to neutralize any deleterious property. Salt,pepper, and vinegar are much more freely employed abroad inpreparing fungi than with us, and with manifest advantage.

It is undoubtedly true that fungi exert an important influencein skin diseases. This seems to be admitted on all hands bymedical men,[E] however much they may differ on the question ofthe extent to which they are the cause or consequence of disease.Facts generally seem to bear out the opinion that a great numberof skin diseases are aggravated, and even produced, by fungi.Robin[F] insists that a peculiar soil is necessary, and Dr. Foxsays it is usually taught that tuberculous, scrofulous, and dirtypeople furnish the best nidus. It is scarcely necessary to enumerate[213]all these diseases, with which medical men are familiar,but simply to indicate a few. There is favus or scall-head,called also “porrigo,” which has its primary seat in the hairfollicles. Plica polonica, which is endemic in Russia, is almostcosmopolitan. Then there is Tinea tonsurans, Alopecia,Sycosis, &c., and in India a more deeply-seated disease, theMadura Foot, has been traced to the ravages of a fungusdescribed under the name ofChionyphe Carteri.[G] It is probablethat the application of different names to the very often imperfectforms of fungi which are associated with differentdiseases is not scientifically tenable. Perhaps one or twocommon moulds, such asAspergillus orPenicillium, lie at thebase of the majority, but this is of little importance here, anddoes not affect the general principle that some skin diseases aredue to fungi.

Whilst admitting that there are such diseases, it must beunderstood that diseases have been attributed to fungi as aprimary cause, when the evidence does not warrant such aconclusion. Diphtheria and thrush have been referred to thedevastations of fungi, whereas diphtheria certainly may anddoes occur without any trace of fungi. Fevers may sometimesbe accompanied by fungoid bodies in the evacuations,but it is very difficult to determine them. The wholequestion of epidemic diseases being caused by the presenceof fungi seems based on most incomplete evidence. Dr.Salisbury was of opinion that camp measles was produced byPuccinia graminis, the pseudospores of which germinated inthe damp straw, disseminated the resultant secondary bodies inthe air, and caused the disease. This has never been verified.Measles, too, has been attributed freely, as well as scarlatina,[H]to fungal influences, and the endeavours to implicate fungi inbeing the cause of cholera have been pertinaciously perseveredin with no conviction. The presence of certain cysts, said tobe those ofUrocystis, derived from rice, was announced by Dr.[214]Hallier, but when it was shown that no such fungus was foundon rice, this phase of the theory collapsed. Special and competentexperts were sent from this country to examine the preparationsand hear the explanations of Dr. Hallier on his theory ofcholera contagion, but they were neither convinced nor satisfied.

As long ago as 1853, Dr. Lauder Lindsay examined andreported on cholera evacuations, and in 1856 he declared—“Itwill be evident that I can see no satisfactory groundwork forthe fungus theory of cholera, which I am not a little surprisedto find still possesses powerful advocates.”[I] And of the examinationsundertaken by him he writes:—“The mycelium andsporules of various species of fungi, constituting various formsof vegetable mould, were found in the scum of the vomit, aswell as of the stools, but only at some stage of decomposition.They are found, however, under similar circumstances, in thevomit and stools of other diseases, and, indeed, in all decomposinganimal fluids, and they are therefore far from peculiar tocholera.”

Some writers have held that the atmosphere is often highlycharged with fungi spores, others have denied the presence oforganic bodies to any extent in the air. The experiments conductedin India by Dr. Cunningham[J] have been convincingenough on this point. This report states that spores and similarcells were of constant occurrence, and were generally present inconsiderable numbers. That the majority of the cells were livingand ready to undergo development on meeting with suitableconditions was very manifest, as in those cases in which preparationswere retained under observation for any length of time,germination rapidly took place in many of the cells; indeed,many spores already germinating were deposited on the slides.In few instances did any development take place beyond the[215]formation of mycelium or masses of toruloid cells, but inone or two distinct sporules were developed on the filamentsarising from some of the larger septate spores, and in a fewothersPenicillium andAspergillus produced their characteristicheads of fructification.

With regard to the precise nature of the spores and othercells present in various instances little can be said, as, unlesstheir development were to be carefully followed out through allits stages, it is impossible to refer them to their correct speciesor even genera. The greater number of them are apparentlyreferable to the old orders of fungi—Sphæronemei,Melanconei,Torulacei,Dematiei, andMucedines, while some probably belongedto thePucciniei andCoæmacei. Amongst those belongingto theTorulacei, the most interesting was a representative ofthe rare genusTetraploa. Distinct green algoid cells occurredin some specimens. Then follow in the report details of observationsmade on the rise and fall of diseases, of which diarrhœa,dysentery, cholera, ague, and dengue were selected and comparedwith the increase or diminution of atmospheric cells. The conclusionsarrived at are:—

“Spores and other vegetable cells are constantly present inatmospheric dust, and usually occur in considerable numbers;the majority of them are living, and capable of growth anddevelopment. The amount of them present in the air appearsto be independent of conditions of velocity and direction of thewind, and their number is not diminished by moisture.

“No connection can be traced between the numbers ofbacteria, spores, &c., present in the air, and the occurrence ofdiarrhœa, dysentery, cholera, ague, or dengue, nor between thepresence or abundance of any special form or forms of cells, andthe prevalence of any of these diseases.

“The amount of inorganic and amorphous particles and otherdébris suspended in the atmosphere is directly dependent onconditions of moisture and velocity of wind.”

This report is accompanied by fourteen large and well-executedplates, each containing hundreds of figures of organic bodies collectedfrom the air between February and September. It is valuable[216]both for its evidence as to the number and character of thespores in the air, and also for the tables showing the relationbetween five forms of disease, and their fluctuations, as comparedwith the amount of spores floating in the atmosphere.

We are fain to believe that we have represented the influenceof fungi on man as far as evidence seems to warrant. Thepresence of forms of mould in some of their incipient conditionsin different diseased parts of the human body, externally andinternally, may be admitted without the assumption that theyare in any manner the cause of the diseased tissues, except insuch cases as we have indicated. Hospital gangrene may bealluded to in this connection, and it is possible that it may bedue to some fungus allied to the crimson spots (blood rain)which occur on decayed vegetation and meat in an incipientstage of decomposition. This fungus was at one time regardedas an algal, at another as animal; but it is much more probablethat it is a low condition of some common mould. The readinesswith which the spores of fungi floating in the atmosphereadhere to and establish themselves on all putrid or corrupt substancesis manifest in the experience of all who have had to dowith the dressing of wounds, and in this case it is a matter ofthe greatest importance that, as much as possible, atmosphericalcontact should be avoided.

Recently a case occurred at the Botanic Gardens at Edinburghwhich was somewhat novel. The assistant to the botanicalprofessor was preparing for demonstration some driedspecimens of a large puff-ball, filled with the dust-like spores,which he accidentally inhaled, and was for some time confinedto his room under medical attendance from the irritation theycaused. This would seem to prove that the spores of somefungi are liable, when inhaled in large quantities, to derangethe system and become dangerous; but under usual and naturalconditions such spores are not likely to be present in the atmospherein sufficient quantity to cause inconvenience. In theautumn a very large number of basidiospores must be presentin the atmosphere of woods, and yet there is no reason tobelieve that it is more unhealthy to breathe the atmosphere of[217]a wood in September or October than in January or May.Dreadful effects are said to be produced by a species of blackrust which attacks the large South of Europe reed,Arundo donax.This is in all probability the same species with that whichattacksArundo phragmitis in this country, the spores of whichproduce violent headaches and other disorders amongst thelabourers who cut the reeds for thatching. M. Michel statesthat the spores from the parasite onArundo donax, either inhaledor injected, produce violent papular eruption on the face,attended with great swelling, and a variety of alarming symptomswhich it is unnecessary to particularize, in various parts ofthe body.[K] Perhaps ifSarcina should ultimately prove to be afungus, it may be added to the list of those which aggravate, ifthey are not the primary cause of, disease in the human subject.

II. What influences can be attributed to fungi upon animalsother than man? Clearly instinct preserves animals from manydangers. It may be presumed that under ordinary circumstancesthere is not much fear of a cow or a sheep poisoningitself in a pasture or a wood. But under extraordinarycircumstances it is not only possible, but very probable, thatinjuries may occur. For instance, it is well known that notonly rye and wheat, but also many of the grasses, are liable toinfection from a peculiar form of fungus called “ergot.” Incertain seasons this ergot is much more common than others,and the belief is strong in those who ought to know somethingof the subject from experience, viz., farmers and graziers, that insuch seasons it is not uncommon for cattle to slip their youngthrough feeding on ergotized grass. Then, again, it is fairlyopen to inquiry whether, in years when “red rust” and“mildew” are more than usually plentiful on grasses, thesemay not be to a certain extent injurious. Without attemptingto associate the cattle plague in any way with fungi ongrass, it is nevertheless a most remarkable coincidence thatthe year in which the cattle disease was most prevalent inthis country was one in which there was—at least in somedistricts—more “red rust” on grasses than we ever remember[218]to have seen before or since; the clothes of a personwalking through the rusty field soon became orange-colouredfrom the abundance of spores. Graziers on this point againseem to be generally agreed, that they do not think “red rust”has been proved to be injurious to cattle. The direct influenceof fungi on quadrupeds, birds, reptilia, &c., seems to be infinitesimallysmall.

Insects of various orders have been observed from time totime to become the prey of fungi.[L] That known at Guadaloupeunder the name ofLa Guêpe Végétale, or vegetable wasp, hasbeen often cited as evidence that, in some instances at least,the fungus attacks the insect whilst still living. Dr. Madiannastates that he has noticed the wasp still living with its incumbranceattached to it, though apparently in the last stage ofexistence, and seeming about to perish from the influence of itsdestructive parasite.[M] This fungus is called by TulasneTorrubiasphecocephala.[N] About twenty-five species of this genus ofsphæriaceous fungi have been described as parasitic on insects.Five species are recorded in South Carolina, one in Pennsylvania,found on the larvæ of the May-bug, and one otherNorth American species on Nocturnal Lepidoptera, one inCayenne, one in Brazil, on the larva of aCicada, and one on aspecies of ant, two in the West Indies, one in New Guinea ona species ofCoccus, and one on a species ofVespa in Senegal.In Australia two species have been recorded, and two are nativesof New Zealand. Dr. Hooker found two in the Khassya mountainsof India, and one American species has also been foundat Darjeeling. It has long been known that one species, whichhas a medicinal repute there, is found in China, whilst threehave been recorded in Great Britain. Opinions are divided asto whether in these instances the fungus causes or is subsequentto the death of the insect. It is generally the belief of entomologiststhat the death of the insect is caused by the fungus.[219]In the case ofIsaria sphingum, which is the conidia form of aspecies ofTorrubia, the moth has been found standing on a leaf,as during life, with the fungus sprouting from its body.

Other and less perfect forms of fungi also attack insects.During the summer of 1826, Professor Sebert collected a greatmany caterpillars ofArctia villica, for the purpose of watchingtheir growth. These insects on arriving at their full size becamequite soft, and then suddenly died. Soon after they becamehard, and, if bent, would easily break into two pieces. Theirbodies were covered with a beautiful shining white mould.If some of the caterpillars affected with the parasitic mouldwere placed on the same tree with those apparently free fromits attack, the latter soon exhibited signs that they also wereattacked in the same manner, in consequence of coming intocontact with each other.[O]

During the spring of 1851, some twelve or twenty specimenswere found from amongst myriads ofCicada septemdecim, which,though living, had the posterior third of the abdominal contentsconverted into a dry, powdery, ochreous-yellow compact massof sporuloid bodies. The outer coverings of that portion ofthe insect were loose and easily detached, leaving the fungoidmatter in the form of a cone affixed by its base to the unaffectedpart of the abdomen of the insect. The fungus may commence,says Dr. Leidy, its attacks upon the larva, develop its mycelium,and produce a sporular mass within the active pupa, when manyare probably destroyed; but should some be only affected so faras not to destroy the organs immediately essential to life, theymight undergo their metamorphosis into the imago, in whichcase they would be affected in the manner previously described.[P]

The common house-fly in autumn is very usually subject tothe attacks of a mouldy fungus calledSporendonema muscæ, orEmpusa muscæ in former times, which is now regarded as theterrestrial condition of one of theSaprolegniei.[Q] The fliesbecome sluggish, and at last fix themselves to some object on[220]which they die, with their legs extended and head depressed,the body and wings soon becoming covered with a minute whitemould, the joints of which fall on the surrounding object. Examplesare readily distinguished when they settle on windowsand thus succumb to their foe. Mr. Gray says that a similarmould has been observed on individuals of the wasp family.

AGryllotalpa was found in a wood near Newark, Delaware,U. S., upon turning over a log. The insect was seen standingvery quietly at the mouth of its oval cell, which is formedin the earth, having a short curved tube to the surface. Upontaking it up it exhibited no signs of movement, though perfectlyfresh and lifelike in appearance. On examining it next morningit still presented no signs of life. Every part of the insect wasperfect, not even the antennæ being broken. Upon feeling it,it was very hard and resistant, and on making an incisionthrough the thorax it exhaled a fungoid odour. The insect hadbeen invaded by a parasitic fungus which everywhere filled theanimal, occupying the position of all the soft tissue, and extendingeven into the tarsal joints. It formed a yellowish or cream-colouredcompact mass.[R]

The destructive silk-worm disease,Botrytis Bassiana, is alsoa fungus which attacks and destroys the living insect, concerningwhich an immense deal has been written, but which has notyet been eradicated. It has also been supposed that a low formor imperfect condition of a mould has much to do with thedisease of bees known as “foul brood.”[S]

Penicillium Fieberi, figured by Corda on a beetle, was doubtlessdeveloped entirely after death, with which event it hadprobably nothing whatever to do.[T] Sufficient, however, hasbeen written to show that fungi have an influence on insect life,and this might be extended to other animal forms, as to spiders,on which one or two species ofIsaria are developed, whilstDr. Leidy has recorded observations onJulus[U] which may be[221]perused with advantage. Fish are subject to a mouldy-lookingparasite belonging to theSaprolegniei, and a similar formattacks the ova of toads and frogs. Gold fish in globes andaquaria are very subject to attack from this mouldy enemy, andalthough we have seen them recover under a constant change ofwater, this is by no means always the case, for in a few weeksthe parasite will usually prevail.

The influence of fungi upon animals in countries other thanEuropean is very little known, except in the case of the speciesofTorrubia found on insects, and the diseases to which silkwormsare subject. Instances have been recorded of the occurrenceof fungoid mycelium—for in most it is nothing more—inthe tissues of animals, in the hard structure of bone and shell,in the intestines, lungs, and other fleshy parts, and in variousorgans of birds.[V] In some of the latter cases it has been describedas a Mucor, in most it is merely cells without sufficientcharacter for determination. It is by no means improbable thatfungi may be found in such situations; the only question withregard to them is whether they are not accidental, and not theproducers of unhealthy or diseased tissues, even when found inproximity thereto.

There is one phase of the influences of fungi on the loweranimals which must not be wholly passed over, and that is therelation which they bear to some of the insect tribes in furnishingthem with food. It is especially the case with theColeoptera that many species seem to be entirely dependent onfungi for existence, since they are found in no other situations.Beetle-hunters tell us that oldPolyporei, and similar fungi ofa corky or woody nature, are always sought after for certainspecies which they seek in vain elsewhere,[W] and those who possessherbaria know how destructive certain minute members ofthe animal kingdom are to their choicest specimens, againstwhose depredations even poison is sometimes unavailing.

Some of the Uredines, asTrichobasis suaveolens andColeosporiumsonchi, are generally accompanied by a little orange larva[222]which preys upon the fungus; and in the United States Dr.Bolles informs us that some species ofÆcidium are so constantlyinfested with this red larva that it is scarcely possibleto get a good specimen, or to keep it from its sworn enemy.MinuteAnguillidæ revel in tufts of mould, and fleshy Agarics,as they pass into decay, become colonies of insect life. SmallLepidoptera, belonging to theTineina, appear to have a likingfor suchPolyporei asP. sulfureus when it becomes dry andhard, orP. squamosus when it has attained a similar condition.Acari andPsocidæ attack dried fungi of all kinds, and speedilyreduce them to an unrecognizable powder.

III. What are the influences exerted by fungi on otherplants? This is a broad subject, but withal an important one,since these influences act indirectly on man as well as on thelower animals. On man, inasmuch as it interferes with the vegetableportion of his food, either by checking its production ordepreciating its quality. On the lower animals, since by thismeans not only is their natural food deteriorated or diminished,but through it injurious effects are liable to be produced by theintroduction of minute fungi into the system. These remarksapply mainly to fungi which are parasitic on living plants. Onthe other hand, the influence of fungi must not be lost sight ofas the scavengers of nature when dealing with dead and decayingvegetable matter. Therefore, as in other instances, we havehere also good and bad influences intermingled, so that it cannotbe said that they are wholly evil, or unmixed good.

Wherever we encounter decaying vegetable matter we meetwith fungi, living upon and at the expense of decay, appropriatingthe changed elements of previous vegetable life to thesupport of a new generation, and hastening disintegration andassimilation with the soil. No one can have observed themycelium of fungi at work on old stumps, twigs, and decayedwood, without being struck with the rapidity and certainty withwhich disintegration is being carried on. The gardener castson one side, in a pile as rubbish, twigs and cuttings from histrees, which are useless to him, but which have all derived muchfrom the soil on which they flourished. Shortly fungi make[223]their appearance in species almost innumerable, sending theirsubtle threads of mycelium deep into the tissues of the woodysubstance, and the whole mass teems with new life. In thismetamorphosis as the fungi flourish so the twigs decay, for thenew life is supported at the expense of the old, and togetherthe destroyers and their victims return as useful constituents tothe soil from whence they were derived, and form fresh pabulumfor a succeeding season of green leaves and sweet flowers. Inwoods and forests we can even more readily appreciate the goodoffices of fungi in accelerating the decay of fallen leaves andtwigs which surround the base of the parent trees. In suchplaces Nature is left absolutely to her own resources, and whatman would accomplish in his carefully attended gardens andshrubberies must here be done without his aid. What we calldecay is merely change; change of form, change of relationship,change of composition; and all these changes are effected byvarious combined agencies—water, air, light, heat, these furnishingnew and suitable conditions for the development of a newrace of vegetables. These, by their vigorous growth, continuewhat water and oxygen, stimulated by light and heat, hadbegun, and as they flourish for a brief season on the fallenglories of the past summer, make preparation for the comingspring.

Unfortunately this destructive power of fungi over vegetabletissues is too often exemplified in a manner which man does notapprove. The dry rot is a name which has been given to theravages of more than one species of fungus which flourishes atthe expense of the timber it destroys. One of these forms ofdry rot fungus isMerulius lacrymans, which is sometimes spokenof as if it were the only one, though perhaps the most destructivein houses. Another isPolyporus hybridus, which attacksoak-built vessels;[X] and these are not the only ones which arecapable of mischief. It appears that the dry rot fungus actsindirectly on the wood, whose cells are saturated with its juice,and in consequence lose their lignine and cellulose, though theirwalls suffer no corrosion. The different forms of decay in wood[224]are accompanied by fungi, which either completely destroy thetissue, or alter its nature so much by the abstraction of thecellulose and lignine, that it becomes loose and friable. Thusfungi induce the rapid destruction of decaying wood. Theseare the conclusions determined by Schacht, in his memoir onthe subject.[Y]

We may allude, in passing, to another phase of destructivenessin the mycelium of fungi, which traverse the soil and interferemost injuriously with the growth of shrubs and trees.The reader of journals devoted to horticulture will not fail tonotice the constant appeals for advice to stop the work of fungiin the soil, which sometimes threatens vines, at others conifers,and at others rhododendrons. Dead leaves, and other vegetablesubstances, not thoroughly and completely decayed, are almostsure to introduce this unwelcome element.

Living plants suffer considerably from the predations of parasiticspecies, and foremost amongst these in importance arethose which attack the cereals. The corn mildew and its accompanyingrust are cosmopolitan, as far as we know, wherevercorn is cultivated, whether in Australia or on the slopes of theHimalayas. The same may also be said of smut, forUstilago isas common in Asia and America as in Europe. We have seen iton numerous grasses as well as on barley from the Punjab, anda species different fromUstilago maydis on the male florets ofmaize from the same locality. In addition to this, we learnthat in 1870 one form made its appearance on rice. It wasdescribed as constituting in some of the infested grains awhitish, gummy, interlaced, ill-defined, thread-like mycelium,growing at the expense of the tissues of the affected organs,and at last becoming converted into a more or less coherentmass of spores, of a dirty green colour, on the exterior of thedeformed grains. Beneath the outer coating the aggregatedspores are of a bright orange red; the central portion has a vesicularappearance, and is white in colour.[Z] It is difficult to[225]determine from the description what this so-calledUstilago maybe, which was said to have affected a considerable portion of thestanding rice crop in the vicinity of Diamond Harbour.

Bunt is another pest (Tilletia caries) which occupies thewhole farinaceous portion of the grains of wheat. Sincedressing the seed wheat has been so widely adopted in thiscountry, this pest has been of comparatively little trouble.Sorghum and the small millets, in countries where these arecultivated for food, are liable to attacks from allied parasites.Ergot attacks wheat and rice as well as rye, but not to such anextent as to have any important influence upon the crop. Twoor three other species of fungi are sometimes locally troublesome,asDilophospora graminis, andSeptoria nodorum on wheat,but not to any considerable extent. In countries where maize isextensively grown it has not only its own species of mildew(Puccinia), but also one of the most enormous and destructivespecies ofUstilago.

A singular parasite on grasses was found by Cesati in Italy,in 1850, infesting the glumes ofAndropogon.[a] It received thename ofCerebella Andropogonis, but it never appears to haveincreased and spread to such an extent as was at first feared.

Even more destructive than any of these is the potatodisease[b] (Peronospora infestans), which is, unfortunately, toowell known to need description. This disease was at one timeattributed to various causes, but long since its ascertained sourcehas been acknowledged to be a species of white mould, whichalso attacks tomatoes, but less vigorously. De Bary has givenconsiderable attention to this disease, and his opinions areclearly detailed in his memoir onPeronospora, as well as in hisspecial pamphlet on the potato disease.[c] One sees the cause ofthe epidemic, he says, in the diseased state of the potato itself,produced either accidentally by unfavourable conditions of soiland atmosphere, or by a depravation that the plant has experienced[226]in its culture. According to these opinions, the vegetationof the parasite would be purely accidental, the disease would beindependent of it, the parasite would be able frequently even tospare the diseased organs. Others see in the vegetation of thePeronospora the immediate or indirect cause of the varioussymptoms of the disease; either that the parasite invades thestalks of the potato, and in destroying them, or, so to speak, inpoisoning them, determines a diseased state of the tubercles, orthat it introduces itself into all the organs of the plant, andthat its vegetation is the immediate cause of all the symptomsof the disease that one meets with in any organ whatever.His observations rigorously proved that the opinions of thelatter were those only which were well founded. All the alterationsseen on examining spontaneous individuals are foundwhen thePeronospora is sown in a nourishing plant. The mostscrupulous examination demonstrates the most perfect identitybetween the cultivated and spontaneous individuals as much inthe organization of the parasite as in the alteration of the plantthat nourishes it. In the experiments that he had made heaffirms that he never observed an individual or unhealthy predispositionof the nourishing plant. It appeared to him, on thecontrary, that the more the plant was healthy, the more themould prospered.

We cannot follow him through all the details of the growthand development of the disease, or of his experiments on thisand allied species, which resulted in the affirmation that themould immediately determines the disease of the tubercles aswell as that of the leaves, and that the vegetation of thePeronospora alone determines the redoubtable epidemic to whichthe potato is exposed.[d] We believe that this same observeris still engaged in a series of observations, with the view,if possible, of suggesting some remedy or mitigation of thedisease.

Dr. Hassall pointed out, many years since, the action offungous mycelium, when coming in contact with cellular tissue,[227]of inducing decomposition, a fact which has been fully confirmedby Berkeley.

Unfortunately there are other species of the same genus ofmoulds which are very destructive to garden produce.Peronosporagangliformis, B., attacks lettuces, and is but too commonand injurious.Peronospora effusa, Grev., is found on spinachand allied plants.Peronospora Schleideniana, D. By., is in someyears very common and destructive to young onions, and fieldcrops of lucerne are very liable to attack fromPeronosporatrifoliorum, D. By.

The vine crops are liable to be seriously affected by a speciesof mould, which is but the conidia form of a species ofErysiphe.This mould, known under the name ofOidium Tuckeri, B.,attacks the vines in hothouses in this country, but on the Continentthe vineyards often suffer severely[e] from its depredations;unfortunately, not the only pest to which the vine is subject, foran insect threatens to be even more destructive.

Hop gardens suffer severely, in some years, from a similardisease; in this instance the mature or ultimate form is perfected.The hop mildew isSphærotheca Castagnei, Lév., whichfirst appears as whitish mouldy blotches on the leaves, soonbecoming discoloured, and developing the black receptacles oneither surface of the leaf. These may be regarded as thecardinal diseases of fungoid origin to which useful plants aresubject in this country.

Amongst those of less importance, but still troublesomeenough to secure the anathemas of cultivators, may be mentionedPuccinia Apii, Ca., often successful in spoiling beds ofcelery by attacking the leaves;Cystopus candidus, Lév., andGlæosporium concentricum, Grev., destructive to cabbages andother cruciferous plants;Trichobasis Fabæ, Lév., unsparingwhen once established on beans;Erysiphe Martii, Lév., in someseasons a great nuisance to the crop of peas.

Fruit trees do not wholly escape, forRœstelia cancellata, Tul.,attacks the leaves of the pear.Puccinia prunorum affects theleaves of almost all the varieties of plum. Blisters caused byAscomyces deformans, B., contort the leaves of peaches, asAscomycesbullatus, B., does those of the pear, andAscomyces juglandis,B., those of the walnut. Happily we do not at presentsuffer fromAscomyces pruni, Fchl., which, on the Continent,attacks young plum-fruits, causing them to shrivel and fall.During the past year pear-blossoms have suffered from what seemsto be a form ofHelminthosporium pyrorum, and the branches aresometimes infected withCapnodium elongatum; but orchards inthe United States have a worse foe in the “black knot,”[f] whichcauses gouty swellings in the branches, and is caused by theSphæria morbosa of Schweinitz.

Cotton plants in India[g] were described by Dr. Shortt assubject to the attacks of a kind of mildew, which from thedescription appeared to be a species ofErysiphe, but on receivingspecimens from India for examination, we found it to beone of those diseased conditions of tissue formerly classed withfungi under the name ofErineum; and a species of Torulaattacks cotton pods after they are ripe. Tea leaves in plantationsin Cachar have been said to suffer from some sort of blight,but in all that we have seen insects appear to be the depredators,although on the decaying leavesHendersonia theicola, Cooke,establishes itself.[h] The coffee plantations of Ceylon suffer fromthe depredations ofHemiliea vastatrix, as well as from insects.[i]Other useful plants have also their enemies in parasitic fungi.

Olive-trees in the south of Europe suffer from the attacks of aspecies ofAntennaria, as do also orange and lemon trees from aCapnodium, which covers the foliage as if with a coating of soot.In fact most useful plants appear to have some enemy to contendwith, and it is fortunate, not only for the plant, but its cultivators,[229]if this enemy is less exacting than is the case with thepotato, the vine, and the hop.

Forestry in Britain is an insignificant interest compared towhat it is in some parts of Europe, in the United States, andin our Indian possessions. In these latter places it becomes amatter of importance to inquire what influence fungi exert onforest trees. It may, however, be predicated that the injurycaused by fungi is far outstripped by insects, and that there arenot many fungi which become pests in such situations. Coniferoustrees may be infested with the species ofPeridermium,which are undoubtedly injurious,Peridermium elatinum, Lk.,distorting and disfiguring the silver fir, asPeridermium Thomsoni,B.,[j] does those ofAbies Smithiana in the Himalayas. Thisspecies occurred at an elevation of 8,000 feet. The leaves becomereduced in length one-half, curved, and sprinkled, sometimesin double rows, with the large sori of this species, whichgives the tree a strange appearance, and at length proves fatal,from the immense diversion of nutriment requisite to support aparasite so large and multitudinous. The dried specimens havea sweet scent resembling violets. In Northern EuropeCæomapinitorquum, D. By., seems to be plentiful and destructive. Allspecies of juniper, both in Europe and the United States, areliable to be attacked and distorted by species ofPodisoma[k] andGymnosporangium.Antennaria pinophila, Fr., is undoubtedlyinjurious, as also are other species ofAntennaria, which probablyattain their more complete development inCapnodium, of whichCapnodium Citri is troublesome to orange-trees in the south ofEurope, and other species to other trees. How far birch-treesare injured byDothidea betulina, Fr., orMelampsora betulina,Lév., or poplars and aspens byMelampsora populina, Lév.,andMelampsora tremulæ, Lév., we cannot say. The species ofLecythea found on willow leaves have decidedly a prejudicialeffect on the growth of the affected plant.

Floriculture has to contend with many fungoid enemies, whichsometimes commit great ravages amongst the choicest flowers.[230]Roses have to contend against the two forms ofPhragmidiummucronatum as well asAsteroma Rosæ. Still more disastrousis a species ofErysiphei, which at first appears like a densewhite mould. This is namedSphærotheca pannosa. Nor is thisall, forPeronospora sparsa, when it attacks roses in conservatories,is merciless in its exactions.[l] Sometimes violets will be distortedand spoiled byUrocystis Violæ. The garden anemone is freelyattacked byÆcidium quadrifidum. Orchids are liable to spotfrom fungi on the leaves, and recently the whole of the choicesthollyhocks have been threatened with destruction by a mercilessfoe inPuccinia malvacearum. This fungus was first made knownto the world as an inhabitant of South America many years ago.It seems next to have come into notoriety in the Australiancolonies. Then two or three years ago we hear of it for thefirst time on the continent of Europe, and last year for the firsttime in any threatening form in our own islands. During thepresent year its ravages are spreading, until all admirers ofhollyhocks begin to feel alarm lest it should entirely exterminatethe hollyhock from cultivation. It is common on wild mallows,and cotton cultivators must be on the alert, for there is aprobability that other malvaceous plants may suffer.

A writer in the “Gardener’s Chronicle” has proposed a remedyfor the hollyhock disease, which he hopes will prove effectual.He says, “This terrible disease has now, for twelve months,threatened the complete annihilation of the glorious family ofhollyhock, and to baffle all the antidotes that the ingenuity ofman could suggest, so rapidly does it spread and accomplish itsdeadly work. Of this I have had very sad evidence, as lastyear at this time I had charge of, if not the largest, one of thelargest and finest collections of hollyhocks anywhere in cultivation,which had been under my special care for eleven years,and up to within a month of my resigning that position I hadobserved nothing uncommon amongst them; but before takingmy final leave of them I had to witness the melancholy spectacleof bed after bed being smitten down, and amongst them manysplendid seedlings, which had cost me years of patience and[231]anxiety to produce. And again, upon taking a share and themanagement of this business, another infected collection fell tomy lot, so that I have been doing earnest battle with this diseasesince its first appearance amongst us, and I must confess that,up to a very short time back, I had come in for a great deal theworst of the fight, although I had made use of every agent Icould imagine as being likely to aid me, and all that manycompetent friends could suggest. But lately I was reminded ofCondy’s patent fluid, diluted with water, and at once procured abottle of the green quality, and applied it in the proportion of alarge tablespoonful to one quart of water, and upon examiningthe plants dressed, twelve hours afterwards, was delighted tofind it had effectually destroyed the disease (which is easilydiscernible, as when it is living and thriving it is of a lightgrey colour, but when killed it becomes of a rusty black).Further to test the power at which the plant was capable ofbearing the antidote without injury, I used it double thestrength. This dose was instant death to the pest, leavingno trace of any injury to the foliage. As to its application,I advocate sponging in all dressings of this description.Syringing is a very ready means, but very wasteful. No doubtsponging consumes more time, but taking into consideration themore effectual manner in which the dressing can be executedalone, it is in the end most economical, especially in regard tothis little parasite. I have found it difficult by syringing, as ithas great power of resisting and throwing off moisture, and ifbut a very few are left living, it is astonishing how quickly itredistributes itself. I feel confident, that by the application ofthis remedy in time another season, I shall keep this collectionclean. I believe planting the hollyhock in large crowded bedsshould be avoided, as I have observed the closer they aregrowing the more virulently does the disease attack them,whereas isolated rows and plants are but little injured.”[m]

The “Gardener’s Chronicle” has also sounded a note of warningthat a species of Uredine has been very destructive to pelargoniumsat the Cape of Good Hope. Hitherto these plants[232]have not suffered much in this country from parasites. Besidesthese, there are many other less troublesome parasites, such asUredo filicum, on ferns;Puccinia Lychnidearum, on leaves ofsweet-william;Uredo Orchidis, on leaves of orchids, &c.

If we would sum up the influences of fungi in a few words, itcould be done somewhat in the following form.

Fungi exert a deleterious influence—

• OnMan,
  • When eaten inadvertently.
  • By the destruction of his legitimate food.
  • In producing or aggravating skin diseases.

• OnAnimals,
  • By deteriorating or diminishing their food supplies.
  • By establishing themselves as parasites on some species.

• OnPlants,
  • By hastening the decay of timber.
  • By establishing themselves as parasites.
  • By impregnating the soil.

But it is not proved that they produce epidemic diseases inman or animals, or that the dissemination of their multitudinousspores in the atmosphere has any appreciable influence on thehealth of the human race. Hence their association with cholera,diarrhœa, measles, scarlatina, and the manifold ills that flesh isheir to, as producing or aggravating causes, must, in the presentstate of our knowledge and experience, be deemed apocryphal.

It commonly happens that one of the first inquiries which thestudent seeks to have answered, after an interest is excited infungi, is—Where, and under what circumstances, are they to befound? The inexperienced, indeed, require some guide, or muchlabour will be expended and patience lost in seeking microscopicforms in just such places as they are least likely to inhabit. Noris it wholly unprofitable or uninteresting for others, who do notclaim to be students, to summarize the habitats of these organisms,and learn how much the circumstances of their immediatesurrounding elements influence production. For reasons whichwill at once be recognized by the mycologist, the most satisfactorymethod of study will be somewhat that of the naturalgroups into which fungi are divided.

Agaricini.—There is such a close affinity between all thegenera of this group that it will be a manifest advantage to taketogether all those fleshy pileate fungi, the fruit of which isborne on folded plates or gills. It must be premised of thisgroup that, for the majority, shade, a moderate amount of moisture,and steady warmth, but not too great heat, are required.A stroll through a wood in autumn will afford good evidence ofthe predilection ofAgaricini, as well as some smaller groups, forsuch spots. A larger proportion will be found in woods, whereshade is afforded, than on open heaths or pastures. Thesewood-loving forms will consist, again, of those which appearon the soil, and those which are found on rotten stumps anddecaying trees. Many of those which grow on trees have a[234]lateral stem, or scarcely any stem at all. It may be remarked,that some species which spring from the soil delight most inthe shelter of particular trees. The Agarics of a beech wood willmaterially differ largely from those in an oak wood, and both willdiffer from those which spring up beneath coniferous trees.

It may be accepted as true of the largest proportion of terrestrialspecies, that if they do not spring directly from rottenleaves, and vegetable débris in the last stage of decay, thesoil will be rich in vegetable humus. A few only occur onsandy spots. The genusMarasmius is much addicted to deadleaves;Russula, to open places in woods, springing immediatelyfrom the soil.Lactarius prefers trees, and when found inexposed situations, occurs mostly under the shadow of trees.[A]Cantharellus, again, is a woodland genus, many of the speciesloving to grow amongst grass or moss, and some as parasites onthe latter.Coprinus is not a genus much addicted to woods, butis rather peculiar in its attachment to man—if such expression,or one even implying domesticity, might be employed—farmyards,gardens, dunghills, the base of old gateposts and railings,in cellars, on plaster walls, and even on old damp carpets.Hygrophorus loves “the open,” whether pastures, lawns, heaths,commons, or up the slopes of mountains, nearly to the top of thehighest found in Great Britain.Cortinarius seems to have apreference for woods, whilstBolbitius affects dung, or a richsoil.Lentinus,Panus,Lenzites, andSchizophyllum all grow onwood. Coming to the subgenera ofAgaricus, we findPleurotus,Crepidotus,Pluteus,Collybia,Pholiota,Flammula,Hypholoma,and some species ofPsathyra growing on wood, old stumps, orcharcoal;Amanita,Tricholoma, andHebeloma most attached towoods;Clitocybe andMycena chiefly amongst leaves;Nolaneaamongst grass;Omphalia andGalera chiefly in swampy places;Lepiota,Leptonia,Psalliota,Stropharia,Psilocybe, andPsathyrellamostly in open places and pastures;Deconica andPanæolusmostly on dung;Entoloma andClitopilus chiefly terrestrial, andthe rest variable.

Of special habitats, we may allude toNyctalis, of whichthe species are parasitic on dead fungi belonging to the genusRussula. One or two species ofAgaricus, such asAgaricustuberosus andAgaricus racemosus, P., grow on decayingAgarics, whilstAgaricus Loveianus flourishes onAgaricusnebularis even before it is thoroughly decayed. A few speciesgrow on dead fir cones, others on old ferns, &c.Agaricuscepœstipes, Sow., probably of exotic origin, grows on old tan inhothouses.Agaricus caulicinalis, Bull, flourishes on old thatch,as well as twigs, &c.Agaricus juncicola, Fr., affects deadrushes in boggy places, whilstAgaricus affricatus, Fr., andAgaricus sphagnicola, B., are attached to bog moss in similarlocalities. Some few species are almost confined to the stems ofherbaceous plants.Agaricus petasatus, Fr.,Agaricus cucumis, P.,andPaxillus panuoides, F., have a preference for sawdust.Agaricus carpophilus, Fr., andAgaricus balaninus, P., have apredilection for beech mast.Agaricus urticœcola, B. and Br.,seems to confine itself to nettle roots.Coprinus radians, Fr.,makes its appearance on plaster walls,Coprinus domesticus, Fr.,on damp carpets. The only epizoic species, according to M.Fries, isAgaricus cerussatus v. nauseosus, which has been metwith in Russia on the carcase of a wolf; this, however, mighthave been accidental. Persoon describedAgaricus Neapolitanus,which was found growing on coffee-grounds at Naples; andmore recently Viviani has described another species,AgaricusCoffeæ, with rose-coloured spores, found on old fermenting coffee-groundsat Genoa.[B] Tratinnick figures a species namedAgaricusMarkii, which was found in wine casks in Austria. ACoprinus has, both in this country and on the Continent, beenfound, after a very short time, on the dressing of wounds, wherethere has been no neglect. A curious case of this kind, whichat the time excited great interest, occurred some fifty years sinceat St. George’s Hospital. Some species appear to confine themselvesto particular trees, some to come up by preference on soilin garden pots. Certain species have a solitary, others a gregarioushabit, and, of the latter,Agaricus grammopodius, Bull,[236]Agaricus gambosus, Fr.,Marasmius oreades, Fr., and some othersgrow in rings. Hence it will be seen that, within certain limits,there is considerable variation in the habitats of theAgaricini.

Boleti do not differ much fromAgaricini in their localization.They seem to prefer woods or borders of woods to pastures,seldom being found in the latter. One species,B. parasiticus,Bull, grows on old specimens ofScleroderma, otherwise they arefor the most part terrestrial.

Polypori also have no wide range of habitat, except in choiceof trees on which to grow, for the majority of them are corticolous.The sectionMesopus, which has a distinct central stem,has some species which prefer the ground.Polyporus tuberaster,P., in Italy springs from thePietra funghaia,[C] and is cultivatedfor food as well asPolyporus avellanus, which is reared fromcharred blocks of cob-nut trees.

In other genera of thePolyporei similar habitats prevail.Merulius lacrymans, Fr., one form of dry rot, occurs in cellars,and too often on worked timber; whilstMerulius himantoides,Fr., is much more delicate, sometimes running over plants inconservatories.

Hydnei.—There is nothing calling for special note on thehabitats of these fungi. The stipitate species ofHydnum aresome of them found in woods, others on heaths, one on fir-cones,while the rest have similar habitats to the species ofPolyporus.

Auricularini.—The generaHymenochœte,Stereum, andCorticium,with some species ofThelephora, run over corticated ordecorticated wood; other species ofThelephora grow on theground. The Pezizoid forms ofCyphella andSolenia, like speciesofPeziza, sometimes occur on bark, and of the former genussome on grasses and others on moss.

Clavariei.—The interesting, often brightly-coloured, tufts ofClavaria are usually found amongst grass, growing directly fromthe ground. Only in rare instances do they occur on dead leavesor herbaceous stems.Calocera probably should be classed withtheTremellini, to which its structure seems more closely allied.The species are developed on wood. The species ofTyphula[237]andPistillaria are small, growing chiefly on dead herbaceousplants. One or two are developed from a kind ofSclerotium,which is in fact a compact perennial mycelium.

Tremellini.—These curious gelatinous fungi are, with rareexceptions, developed on branches or naked wood;Tremellaversicolor, B. and Br., one of the exceptions, being parasitic on aspecies ofCorticium, andTremella epigæa, B. and Br., spreadingover the naked soil. This completes our rapid survey of thehabitats of theHymenomycetes. Very few of them are reallydestructive to vegetation, for the Agarics and Polypori found ongrowing trees are seldom to be seen on vigorous, but rather ondead branches or partly-decayed trunks.

TheGasteromycetes are far less numerous in species, and alsoin individuals, but their habitats are probably more variable.TheHypogæi, or subterranean species, are found either near thesurface or buried in the soil, usually in the neighbourhood of trees.

Phalloidei.—In most cases the species prefer woody places.They are mostly terrestrial, and have the faculty of making theirpresence known, even when not seen, by the fetid odour whichmany of them exhale. Some of them occur in sandy spots.

Podaxinei.—These resemble in their localities theTrichogastres.Species ofPodaxon affect the nests of Termites intropical countries.[D] Others are found growing amongst grass.

Trichogastres.—These are chiefly terrestrial. The rare butcuriousBatarrea phalloides, P., has been found on sand-hills,and in hollow trees.Tulostoma mammosum, Fr., occurs on oldstone walls, growing amongst moss.Geaster striatus, D. C.,was at one time usually found on the sand of the Denes at GreatYarmouth. AlthoughLycoperdon giganteum, Batsch, occursmost frequently in pastures, or on hedge banks in fields, wehave known it to occur annually for some consecutive yearsin a garden near London. The species ofScleroderma seem toprefer a sandy soil.Aglœocystis is rather an anomalous genus,occurring on the fruit heads ofCyperus, in India.Broomeiaoccurs at the Cape on rotten wood.

Myxogastres.—Rotten wood is one of the most favoured ofmatrices on which these fungi develop themselves; some ofthem, however, are terrestrial.Æthalium will grow on spenttan and other substances. Species ofDiderma flourish onmosses, jungermanniæ, grass, dead leaves, ferns, &c.Angioridiumsinuosum, Grev., will run over growing plants of differentkinds, andSpumaria, in like manner, encrusts living grasses.Badhamia not only flourishes on dead wood, but one species isfound on the fading leaves of coltsfoot which are still green.Craterium runs over almost any substance which lies in its way.Licea perreptans was found in a cucumber frame heated withspent hops. One or twoMyxogastres have been found on lead,or even on iron which had been recently heated. Sowerbyfound one on cinders, in one of the galleries of St. Paul’sCathedral.

Nidulariacei grow on the ground, or on sticks, twigs, chips,and other vegetable substances, such as sawdust, dung, androtten wood.

TheConiomycetes consist of two sections, which are based ontheir habitats. In one section the species are developed on deador dying plants, in the other they are parasitic on living plants.The former includes theSphæronemei, which are variable in theirproclivities, although mostly preferring dead herbaceous plantsand the twigs of trees. The exceptions are in favour ofSphæronema,some of which are developed upon decaying fungi. In thelarge genera,Septoria,Ascochyta,Phyllosticta,Asteroma, &c.,the favourite habitat is fading and dying leaves of plants of allkinds. In the majority of cases these fungi are not autonomous,but are merely the stylosporous conditions ofSphæria. Theyare mostly minute, and the stylospores are of the simplest kind.TheMelanconiei have a preference for the twigs of trees, burstingthrough the bark, and expelling the spores in a gelatinousmass. A few of them are foliicolous, but the exceptionsare comparatively rare, and are represented chiefly inGlœosporium,species of which are found also on apples, peaches,nectarines, and other fruits. TheTorulacei are superficial,having much of the external appearance of the black moulds,[239]and like them are found on decaying vegetable substances, oldstems of herbaceous plants, dead twigs, wood, stumps of trees, &c.The exceptions are in favour of such species asTorula sporendonema,which is the red mould of cheese, and also occurs on rats’dung, old glue, &c., andSporendonema Muscæ, which is onlythe conidia of a species ofAchlya. One species ofBactridiumis parasitic on the hymenium ofPeziza, andEchinobotryumatrum, on the flocci of black moulds.

In the other section ofConiomycetes the species are parasiticupon, and destructive to, living plants, very seldom being foundon really dead substances, and even in such rare cases undoubtedlydeveloped during the life of the tissues. Mostly theultimate stage of these parasites is exhibited in the ruptured cuticle,and the dispersion of the dust-like spores; but inTilletiacaries,Thecaphora hyalina, andPuccinia incarcerata, they remainenclosed within the fruit of the foster-plant. The differentgenera exhibit in some instances a liking for plants of certainorders on which to develop themselves.Peridermium attackstheConiferæ;Gymnosporangium andPodisoma the differentspecies of Juniper;Melampsora chiefly the leaves of deciduoustrees;Rœstelia attaches itself to pomaceous trees, whilstGraphiolaaffects thePalmaceæ, andEndophyllum the succulentleaves of houseleek. InÆcidium a few orders seem to be moreliable to attack than others, as theCompositæ,Ranunculaceæ,Leguminosæ,Labiatæ, &c., whilst others, as theGraminaceæ,Ericaceæ,Malvaceæ,Cruciferæ, are exempt. There are, nevertheless,very few natural orders of phanerogamous plants inwhich some one or more species, belonging to this section of theConiomycetes, may not be found; and the same foster-plant willoccasionally nurture several forms. Recent investigations tendto confirm the distinct specific characters of the species foundon different plants, and to prove that the parasite of one hostwill not vegetate upon another, however closely allied. Thisadmission must not, however, be accepted as universally applicable,and therefore it should not be assumed, because acertain parasite is found developed on a special host, that it isdistinct, unless distinctive characters, apart from habitat, can be[240]detected.Æcidium compositarum andÆcidium ranunculacearum,for instance, are found on various composite and ranunculaceousplants, and as yet no sufficient evidence has been adduced toprove that the different forms are other than varieties of one ofthe two species. On the other hand, it is not improbable thattwo species ofÆcidium are developed on the common berberry,as De Bary has indicated that two species of mildew,Pucciniagraminis, andPuccinia straminis, are found on wheat.

Hyphomycetes.—The moulds are much more universal in theirhabitats, especially theMucedines. TheIsariacei have a predilectionfor animal substances, though not exclusively. Somespecies occur on dead insects, others on decaying fungi, and therest on sticks, stems, and rotten wood. TheStilbacei have alsosimilar habitats, except that the species ofIllosporium seem to beconfined to parasitism on lichens. The black moulds,Dematiei,are widely diffused, appearing on herbaceous stems, twigs, bark,and wood in most cases, but also on old linen, paper, millboard,dung, rotting fruit, &c., whilst forms ofCladosporium andMacrosporiumare met with on almost every kind of vegetable substancein which the process of decay has commenced.

Mucedines, in some instances, have not been known to appearon more than one kind of matrix, but in the far greater numberof cases they nourish on different substances.Aspergillusglaucus andPenicillium crustaceum are examples of these universalMucedines. It would be far more difficult to mentionsubstances on which these moulds are never developed than toindicate where they have been found. With the species ofPeronospora it is different, for these are truly parasitic on livingplants, and, as far as already known, the species are confined tocertain special plants, and cannot be made to vegetate on anyother. The species which causes the potato murrain, althoughliable to attack the tomato, and other species ofSolanaceæ, doesnot extend its ravages beyond that natural order, whilstPeronosporaparasitica confines itself to cruciferous plants. Onespecies is restricted to theUmbelliferæ, another, or perhaps two,to theLeguminosæ, another toRubiaceæ, two or three toRanunculaceæ,and two or three toCaryophyllaceæ. All the experiments[241]made by De Bary seem to prove that the species ofPeronospora will only flourish on certain favoured plants, to theexclusion of all others. The non-parasitic moulds are scarcelyexclusive. InOidium some species are parasitic, but probablyall the parasitic forms are states ofErysiphe, the non-parasiticalone being autonomous; of these one occurs onPorrigo lupinosa,others on putrefying oranges, pears, apples, plums, &c.,and one on honeycomb.Acrospeira grows in the interior ofsweet chestnuts, and we have seen a species growing within thehard testa of the seeds ofGuilandina Bondue, from India, towhich there was no external opening visible, and which wasbroken with considerable difficulty. SeveralMucedines aredeveloped on the dung of various animals, and seldom on anythingelse.

ThePhysomycetes consist of two orders,Antennariei andMucorini,which differ from each other almost as much in habitatas in external appearance. The former, if represented byAntennaria,runs over the green and fading leaves of plants, forminga dense black stratum, like a congested layer of soot; or inZasmidium,the common cellar fungus, runs over the walls, bottles,corks, and other substances, like a thick sooty felt. In theMucorini,as in theMucedines, there is usually less restriction toany special substance.Mucor mucedo occurs on bread, paste,preserves, and various substances; other species ofMucor seemto have a preference for dung, and some for decaying fungi, butrotting fruits are nearly sure to support one or other of thespecies. The two known species of the curious genusPilobolus,as well asHydrophora, are confined to dung.Sporodinia,Syzygites,&c., nourish on rotten Agarics, where they pass throughtheir somewhat complicated existence.

TheAscomycetes contain an immense number of species, and ingeneral terms we might say that they are found everywhere. TheTuberacei are subterraneous, with a preference for calcareous districts.ThePerisporiacei are partly parasitical and partly not.TheErysiphei include those of the former which flourish at theexpense of the green parts of roses, hops, maples, poplars, peas,and many other plants, both in Europe and in North America,[242]whilst in warmer latitudes the genusMeliola appears to taketheir place.

TheElvellacei are fleshy fungi, of which the larger forms areterrestrial;Morchella,Gyromitra, andHelvella mostly growingin woods,Mitrula,Spathularia, andLeotia in swampy places,andGeoglossum amongst grass. The very large genusPezizais divided into groups, of whichAleuriæ are mostly terrestrial.This group includes nearly all the large-sized species, althougha few belong to the next.Lachneæ are partly terrestrial andpartly epiphytal, the most minute species being found on twigsand leaves of dead plants. InPhialea the species are nearlyentirely epiphytal, as is also the case inHelotium and alliedgenera. Some species ofPeziza are developed from the curiousmasses of compact mycelium calledSclerotia. A few are rathereccentric in their habitats.P. viridaria,P. domestica, andP.hœmastigma, grow on damp walls;P. granulata and some otherson dung.Peziza Bullii was found growing on a cistern.P. theleboloidesappears in profusion on spent hops.P. episphæria,P. clavariarum,P. vulgaris,Helotium pruinosum, and others areparasitic on old fungi. One or two species ofHelotium grow onsubmerged sticks, so as to be almost aquatic, a circumstance ofrare occurrence in fungi. OtherDiscomycetes are similar intheir habitats to theElvellacei. The group to which the oldgenusAscobolus belongs is in a great measure confined to thedung of various animals, although there are two or three lignicolousspecies; andAscophanus saccharinus was first found onold leather,Ascophanus testaceus on old sacking, &c.Ascomycesis, perhaps, the lowest form which ascomycetous fungi assume,and the species are parasitic on growing plants, distorting theleaves and fruit, constituting themselves pests to the cultivatorsof peach, pear, and plum trees.

TheSphæriacei include a very large number of species whichgrow on rotten wood, bark, sticks, and twigs; another group isdeveloped on dead herbaceous stems; yet another is confined todead or dying leaves. One genus,Torrubia, grows chiefly oninsects;Hypomyces is parasitic on dead fungi;Claviceps is developedfrom ergot,Poronia on dung,Polystigma on living leaves,[243]as well as some species ofStigmatea andDothidea. Of thegenusSphæria, a considerable number are found on dung, nowincluded by some authors underSordaria andSporormia, generafounded, as we think, on insufficient characters.A limited number of species are parasitic onlichens, and one species only is known to beaquatic.

Fig. 109.—Torrubia militaris on pupa of a moth.

We have thus rapidly, briefly, and casuallyindicated the habitats to which the majorityof the larger groups of fungi are attached,regarding them from a systematic point ofview. There is, however, another aspect fromwhich we might approach the subject, takingthe host or matrix, or in fact the habitat, asthe basis, and endeavouring to ascertain whatspecies of fungi are to be found in such positions.This has partly been done by M. Westendorp;[E]but every year adds considerably tothe number of species, and what might havebeen moderately accurate twelve years since can scarcely be sonow. To carry this out fully a special work would be necessary,so that we shall be content to indicate or suggest, by meansof a few illustrations, the forms of fungi, often widely distinctin structure and character, to be found in the same locality.

The stems of herbaceous plants are favourite habitats forminute fungi. The old stems of the common nettle, for example,perform the office of host to about thirty species.[F] Ofthese about nine arePezizæ, and there are as many sphæriaceousfungi, whilst three species ofDendryphium, besides other moulds,select this plant. Some of these have not hitherto been detectedgrowing on any other stems, such asSphæria urticæ andLophiostomasex-nucleatum, to which we might addPeziza fusarioides andDendryphium griseum. These do not, however, include the wholeof the fungi found on the nettle, since others are parasitic upon[244]its living green parts. Of these may be namedÆcidium urticæandPeronospora urticæ, as well as two species described byDesmazières asFusisporium urticæ andSeptoria urticæ. Henceit will be seen how large a number of fungi may attach themselvesto one herbaceous plant, sometimes whilst living, but mostextensively when dead. This is by no means a solitary instance,but a type of what takes place in many others. If, on the otherhand, we select such a tree as the common lime, we shall findthat the leaves, twigs, branches, and wood bear, according toM. Westendorp,[G] no less than seventy-four species of fungi, andof these eleven occur on the leaves. The spruce fir, according tothe same authority, nourishes one hundred and fourteen species,and the oak not less than two hundred.

It is curious to note how fungi are parasitic upon each otherin some instances, as in that ofHypomyces, characteristic of thegenus, in which sphæriaceous fungi make hosts of deadLactarii,&c. We have already alluded toNyctalis, growing on decayedRussulæ, toBoletus parasiticus, flourishing on oldScleroderma,and toAgaricus Loveianus, on the pileus ofAgaricus nebularis.To these we may addTorrubia ophioglossoides andT. capitata,which flourish on decayingElaphomyces,Stilbum tomentosum onoldTrichia,Peziza Clavariarum on deadClavaria, and manyothers, the mere enumeration of which would scarcely proveinteresting. A very curious little parasite was found by Messrs.Berkeley and Broome, and named by themHypocrea inclusa,which makes itself a home in the interior of truffles. Mucorsand moulds flourish on dead and decaying Agarics, and otherfleshy forms, in great luxuriance and profusion.Mucor ramosusis common onBoletus luridus, andSyzygites megalocarpus onAgarics, as well asAcrostalagmus cinnabarinus. A very curiouslittle parasite,Echinobotryum atrum, occurs like minute noduleson the flocci of black moulds.Bactridium Helvellæ usurps thefructifying disc of species ofPeziza. A smallSphinctrina isfound both in Britain and the United States on oldPolypori.InSphæria nigerrima,Nectria episphæria, and two or three[245]others, we have examples of one sphæriaceous fungus growingupon another.

Mr. Phillips has recently indicated the species of fungi foundby him on charcoal beds in Shropshire,[H] but, useful as it is, thatonly refers to one locality. A complete list of all the fungiwhich have been found growing on charcoal beds, burnt soil,or charred wood, would be rather extensive. The fungi foundin hothouses and stoves are also numerous, and often of considerableinterest from the fact that they have many of themnever been found elsewhere. Those found in Britain,[I] for instance,are excluded from the British Flora as doubtful, because,growing upon or with exotic plants, they are deemed to be ofexotic origin, yet in very few cases are they known to be inhabitantsof any foreign country. Some species found in suchlocalities are not confined to them, asAgaricus cœpestipes,Agaricus cristatus,Æthalium vaporarium, &c. It is somewhatsingular that certain species have a predilection for growing inproximity with other plants with which they do not appear tohave any more intimate relation. Truffles, for instance, in associationwith oaks,Peziza lanuginosa under cedar-trees,Hydnangiumcarneum about the roots ofEucalypti, and numerousspecies ofAgaricini, which are only found under trees of a particularkind. As might be anticipated, there is no more fertilehabitat for fungi than the dung of animals, and yet the kindsfound in such locations belong to but a few groups. AmongsttheDiscomycetes, a limited number of the genusPeziza arefimicolous, but the allied genusAscobolus, and its own immediateallies, include amongst its species a large majority that arefound on dung. If we take the number of species at sixty-four,there are only seven or eight which do not occur on dung, whilstfifty-six are fimicolous. The species ofSphæria which are foundon the same substances are also closely allied, and some Continentalauthors have grouped them under the two proposed[246]generaSporormia andSordaria, whilst Fuckel[J] proposes a distinctgroup ofSphæriacei, under the name ofFimicoli, in whichhe includes as generaCoprolepa,Hypocopra,Delitschia,Sporormia,Pleophragmia,Malinvernia,Sordaria, andCercophora. Thetwo species ofPilobolus, and some ofMucor, are also found ondung,Isaria felina on that of cats,Stilbum fimetarium and afew other moulds, and amongst Agarics some species ofCoprinus.Animal substances are not, as a rule, prolific in the productionof fungi.Ascobolus saccharinus and one or two others havebeen found upon old leather.Onygena of two or three speciesoccurs on old horn, hoofs, &c. Cheese, milk, &c., afford a fewforms, but the largest number infest dead insects, either underthe mouldy form ofIsaria or the more perfect condition ofTorrubia,and occasionally under other forms.

Robin[K] has recorded that three species ofBrachinus, of theorder Coleoptera, have been found infected, whilst living, with aminute yellow fungus which he callsLaboulbenia Rougeti, andthe same species has been noted on other beetles.TorrubiaMelolonthæ[L] has been described by Tulasne as occurring on themaybug or cockchafer, which is allied to, if not identical with,Cordyceps Ravenelii, B. and C., and also that described and figuredby M. Fougeroux de Bondaroy.[M]Torrubia curculionum, Tul.,occurs on several species of beetles, and seems to be by no meansuncommon in Brazil and Central America.Torrubia cœspitosa,Tul., which may be the same asCordyceps Sinclairi, B.,[N] is foundon the larvæ ofOrthoptera in New Zealand,Torrubia Miqueliion the larvæ ofCicada in Brazil, andTorrubia sobolifera on thepupæ ofCicada in the West Indies. A romantic account isgiven of this in an extract cited by Dr. Watson in his communicationto the Royal Society.[O] “The vegetable fly is found inthe island Dominica, and (excepting that it has no wings) resembles[247]the drone, both in size and colour, more than any otherEnglish insect. In the month of May it buries itself in theearth and begins to vegetate. By the latter end of July, thetree is arrived at its full growth, and resembles a coral branch,and is about three inches high, and bears several little pods,which, dropping off, become worms, and from thence flies, likethe English caterpillar.”Torrubia Taylori, which grows fromthe caterpillar of a large moth in Australia, is one of the finestexamples of the genus.Torrubia Robertsii, from New Zealand,has long been known as attacking the larva ofHepialusvirescens. There are several other species on larvæ of differentinsects, on spiders, ants, wasps, &c., and one or two on matureLepidoptera, but the latter seem to be rare.

That fungi should make their appearance and flourish inlocalities and conditions generally considered inimical to vegetablelife is no less strange than true. We have already alluded tothe occurrence of some species on spent tan, and some othershave been found in locations as strange. We have seen a yellowmould resemblingSporotrichum in the heart of a ball of opium,also a white mould appears on the same substance, and morethan one species is troublesome in the opium factories of India.A mould made its appearance some years since in a coppersolution employed for electrotyping in the Survey Departmentof the United States,[P] decomposing the salt, and precipitatingthe copper. Other organisms have appeared from time to timein various inorganic solutions, some of which were considereddestructive to vegetable life, and it is not improbable that someof these organisms were low conditions of mould. It may welloccasion some surprise that fungi should be found growingwithin cavities wholly excluded from the external air, as in thehollow of filberts, and the harder shelled nuts ofGuilandina, inthe cavities of the fruit of tomato, or in the interior of an egg.It is scarcely less extraordinary thatHypocrea inclusa shouldflourish in the interior of a kind of truffle.

From the above it will be concluded that the habitats of fungiare exceedingly variable, that they may be regarded as almost[248]universal wherever decaying vegetable matter is found, andthat under some conditions animal substances, especially ofvegetable feeders, such as insects, furnish a pabulum for theirdevelopment.

A very curious and interesting inquiry presents itself to ourminds, which is intimately related to this subject of the habitatsof fungi. It shapes itself into a sort of “puzzle for the curious,”but at the same time one not unprofitable to think about. Howis the occurrence of new and before unknown forms to beaccounted for in a case like the following?[Q]

It was our fortune—good fortune as far as this investigationwas concerned—to have a portion of wall in our dwelling persistentlydamp for some months. It was close to a cisternwhich had become leaky. The wall was papered with “marbled”paper, and varnished. At first there was for some time nothingworthy of observation, except a damp wall—decidedly damp,discoloured, but not by any means mouldy. At length, andrather suddenly, patches of mould, sometimes two or threeinches in diameter, made their appearance. These were at firstof a snowy whiteness, cottony and dense, just like large tufts ofcotton wool, of considerable expansion, but of miniature elevation.They projected from the paper scarcely a quarter of aninch. In the course of a few weeks the colour of the tuftsbecame less pure, tinged with an ochraceous hue, and resemblingwool rather than cotton, less beautiful to the naked eye, or undera lens, and more entangled. Soon after this darker patchesmade their appearance, smaller, dark olive, and mixed with, orclose to, the woolly tufts; and ultimately similar spots of adendritic character either succeeded the olive patches, or wereindependently formed. Finally, little black balls, like smallpin heads, or grains of gunpowder, were found scattered aboutthe damp spots. All this mouldy forest was more than sixmonths under constant observation, and during that period washeld sacred from the disturbing influences of the housemaid’sbroom and duster.

Curiosity prompted us from the first to submit the mouldy[249]denizens of the wall to the microscope, and this curiosity wasincreased week by week, on finding that none of the formsfound vegetating on nearly two square yards of damp wallcould be recognized as agreeing specifically with any describedmoulds with which we were acquainted. Here was a problemto be solved under the most favourable conditions, a forest ofmould indoors, within a few yards of the fireside, growing quitenaturally, and all strangers. Whence could these new formsproceed?

The cottony tufts of white mould, which were the first toappear, had an abundant mycelium, but the erect threads whichsprang from this were for a long time sterile, and closely interlaced.At length fertile threads were developed in tufts, mixedwith the sterile threads. These fruit-bearers were shorter andstouter, more sparingly branched, but beset throughout nearlytheir whole length with short patent, alternate branchlets.These latter were broadest towards the apex, so as to be almostclavate, and the extremity was beset with two or three shortspicules. Each spicule was normally surmounted by an obovatespore. The presence of fertile threads imparted the ochraceoustint above alluded to. This tint was slight, and perhaps wouldnot have been noticed, but from the close proximity of the snow-whitetufts of barren threads. The fertile flocci were decumbent,probably from the weight of the spores, and the tufts were alittle elevated above the surface of the matrix. This mouldbelonged clearly to theMucedines, but it hardly accorded wellwith any known genus, although most intimately relatedtoRhinotrichum, in which it was placed asRhinotrichumlanosum.[R]

The white mould having become established for a week ortwo, small blackish spots made their appearance on the paper,sometimes amongst thin patches of the mould, and sometimesoutside them. These spots, at first cloudy and indefinite, variedin size, but were usually less than a quarter of an inch indiameter. The varnish of the paper was afterwards pushed off[250]in little translucent flakes or scales, an erect olivaceous mouldappeared, and the patches extended to nearly an inch indiameter, maintaining an almost universal circular form. Thisnew mould sometimes possessed a dirty reddish tint, but wascommonly dark olive. There could be no mistake about thegenus to which this mould belonged; it had all the essentialcharacters ofPenicillium. Erect jointed threads, branched inthe upper portion in a fasciculate manner, and bearing longbeaded threads of spores, which formed a tassel-like head, atthe apex of each fertile thread. Although at first reminded ofPenicillium olivaceum, of Corda, by the colour of this species, itwas found to differ in the spores being oblong instead of globose,and the ramifications of the flocci were different. Unable againto find a described species ofPenicillium with which this newmould would agree, it was described under the name ofPenicilliumchartarum.[S]

Almost simultaneously, or but shortly after the perfectionof the spores ofPenicillium, other and very similar patchesappeared, distinguished by the naked eye more particularly bytheir dendritic form. This peculiarity seemed to result from thedwarfed habit of the third fungus, since the varnish, thoughcracked and raised, was not cast off, but remained in smallangular fragments, giving to the spots their dendritic appearance,the dark spores of the fungus protruding through the fissures.This same mould was also found in many cases growing in thesame spots amongstPenicillium chartarum, but whether fromthe same mycelium could not be determined.

The distinguishing features of this fungus consist in anextensive mycelium of delicate threads, from which arisenumerous erect branches, bearing at the apex dark brownopaque spores. Sometimes the branches were again shortlybranched, but in the majority of instances were single. Theseptate spores had from two to four divisions, many of themdivided again by cross septa in the longitudinal direction of thespore, so as to impart a muriform appearance. As far as thestructure and appearance of the spores are concerned, they resembled[251]those ofSporidesmium polymorphum, under which namespecimens were at first published,[T] but this determination wasnot satisfactory. The mycelium and erect threads are much toohighly developed for a good species ofSporidesmium, althoughthe name ofSporidesmium alternaria was afterwards adopted.In fresh specimens of this fungus, when seenin situ by a half-inchobjective, the spores appear to be moniliform, but if so, allattempts to see them so connected, when separated from thematrix, failed. On one occasion, a very immature condition wasexamined, containing simple beaded, hyaline bodies, attachedto each other by a short neck. The same appearance ofbeaded spores, when seenin situ, was recognized by a mycologicalfriend, to whom specimens were submitted for confirmation.[U]

The last production which made its appearance on our wall-paperburst through the varnish as little black spheres, likegrains of gunpowder. At first the varnish was elevated bypressure from beneath, then the film was broken, and the littleblackish spheres appeared. These were, in the majority of cases,gregarious, but occasionally a few of the spheres appearedsingly, or only two or three together. As the whole surface ofthe damp paper was covered by these different fungi, it wasscarcely possible to regard any of them as isolated, or to declarethat one was not connected with the mycelium of the others.The little spheres, when the paper was torn from the wall, werealso growing from the under surface, flattened considerably bythe pressure. The spherical bodies, or perithecia, were seatedon a plentiful hyaline mycelium. The walls of the perithecia,rather more carbonaceous than membranaceous, are reticulated,reminding one of the conceptacles ofErysiphe, to which theperithecia bear considerable resemblance. The ostiolum is so[252]obscure that we doubt its existence, and hence the closer affinityof the plant to thePerisporiacei than to theSphæriacei. Theinterior of the perithecium is occupied by a gelatinous nucleus,consisting of elongated cylindrical asci, each enclosing eightglobose hyaline sporidia, with slender branched paraphyses. Anew genus has been proposed for this and another similar form,and the present species bears the name ofOrbicula cyclospora.[V]

The most singular circumstance connected with this narrativeis the presence together of four distinctly different species offungi, all of them previously unknown and undescribed, and notrace amongst them of the presence of any one of the very commonspecies, which would be supposed to develop themselves undersuch circumstances. It is not at all unusual forSporocybealternata, B., to appear in broad black patches on damp paperedwalls, but in this instance not a trace was to be found. Whatwere the peculiar conditions present in this instance which ledto the manifestation of four new forms, and none of the oldones? We confess that we are unable to account satisfactorilyfor the mystery, but, at the same time, feel equally unwilling toinvent hypotheses in order to conceal our own ignorance.

The cultivation of fungi in this country for esculent purposesis confined to a single species, and yet there is no reason why,by a series of well-conducted experiments, means should notbe devised for the cultivation of others, for instance,Marasmiusorcades, and the morel. Efforts have been made on theContinent for the cultivation of truffles, but the success hashitherto been somewhat doubtful. For the growth of the commonmushroom, very little trouble and care is required, andmoderate success is certain. A friend of ours some years sincewas fortunate enough to have one or two specimens of the largepuff-ball,Lycoperdon giganteum, growing in his garden. Knowingits value, and being particularly fond of it when fried forbreakfast, he was anxious to secure its permanence. The spoton which the specimens appeared was marked off and guarded,so that it was never desecrated by the spade, and the soilremained consequently undisturbed. Year after year, so longas he resided on the premises, he counted upon and gatheredseveral specimens of the puff-ball, the mycelium continuing toproduce them year after year. All parings, fragments, &c., notutilized of the specimens eaten were cast on this spot to rot, sothat some of the elements might be returned to the soil. Thiswas not true cultivation perhaps, as the fungus had first establisheditself, but it was preservation, and had its reward. Itmust be admitted, however, that the size and number of specimensdiminished gradually, probably from exhaustion of thesoil. This fungus, though strong, is much approved by many[254]palates, and its cultivation might be attempted. Burying a ripespecimen in similar soil, and watering ground with the spores,has been tried without success.[A]

As to the methods adopted for cultivation of the common mushroom,it is unnecessary to detail them here, as there are severalspecial treatises devoted to the subject, in which the particularsare more fully given than the limits of this chapter will permit.[B]Recently, M. Chevreul exhibited at the French Academy somesplendid mushrooms, said to have been produced by the followingmethod: he first develops the mushrooms by sowing spores ona pane of glass, covered with wet sand; then he selects the mostvigorous individuals from among them, and sows, or plants theirmycelium in a cellar in a damp soil, consisting of gardener’smould, covered with a layer of sand and gravel two inches thick,and another layer of rubbish from demolitions, about an inch deep.The bed is watered with a diluted solution of nitrate of potash,and in about six days the mushrooms grow to an enormoussize.[C] The cultivation of mushrooms for the market, even inthis country, is so profitable, that curious revelations sometimescrop up, as at a recent trial at the Sheriffs’ Court for compensation[255]by the Metropolitan Railway Company for premises andbusiness of a nurseryman at Kensington. The Railway hadtaken possession of a mushroom-ground, and the claim forcompensation was £716. It was stated in evidence that theprofits on mushrooms amounted to 100 or 150 per cent. Onewitness said if £50 were expended, in twelve months, or perhapsin six months, the sum realized would be £200.

Immense quantities of mushrooms are produced in Paris, asis well known, in caves, and interesting accounts have beenwritten of visits to these subterranean mushroom-vaults of thegay city. In one of these caves, at Montrouge, the proprietorgathers largely every day, occasionally sending more than400 pounds weight per day to market, the average beingabout 300 pounds. There are six or seven miles’ run ofmushroom-beds in this cave, and the owner is only one of alarge class who devote themselves to the culture of mushrooms.Large quantities of preserved mushrooms are exported, onehouse sending to England not less than 14,000 boxes in a year.Another cave near Frépillon was in full force in 1867, sendingas many as 3,000 pounds of mushrooms to the Parisian marketsdaily. In 1867, M. Renaudot had over twenty-one miles ofmushroom-beds in one great cave at Méry, and in 1869 therewere sixteen miles of beds in a cave at Frépillon. The temperatureof these caves is so equal that the cultivation of themushroom is possible at all seasons of the year, but the bestcrops are gathered in the winter.

Mr. Robinson gives an excellent account, not only of the subterranean,but also of the open-air culture of mushrooms aboutParis. The open-air culture is never pursued in Paris duringthe summer, and rarely so in this country.[D] What might betermed the domestic cultivation of mushrooms is easy, that is,the growth by inexperienced persons, for family consumption, ofa bed of mushrooms in cellars, wood-houses, old tubs, boxes, orother unconsidered places. Even in towns and cities it is notimpracticable, as horse-dung can always be obtained from mews[256]and stables. Certainly fungi are never so harmless, or seldomso delicious, as when collected from the bed, and cooked at once,before the slightest chemical change or deterioration could possiblytake place.

Mr. Cuthill’s advice may be repeated here. He says:—“Imust not forget to remind the cottager that it would be ashilling or two a week saved to him during the winter, if he hada good little bed of mushrooms, even for his own family, to saynothing about a shilling or two that he might gain by selling tohis neighbours. I can assure him mushrooms grow faster thanpigs, and the mushrooms do not eat anything; they only wanta little attention. Addressing myself to the working classes, Iadvise them, in the first place, to employ their children or otherscollecting horse-droppings along the highway, and if mixed witha little road-sand, so much the better. They must be depositedin a heap during summer, and trodden firmly. They will heata little, but the harder they are pressed the less they will heat.Over-heating must be guarded against; if the watch or trialstick which is inserted into them gets too hot for the hand tobear, the heat is too great, and will destroy the spawn. In thatcase artificial spawn must be used when the bed is made up, butthis expedient is to be avoided on account of the expense. Theeasiest way for a cottager to save his own spawn would be todo so when he destroys his old bed; he will find all round theedges or driest parts of the dung one mass of superior spawn;let him keep this carefully in a very dry place, and when hemakes up his next bed it can then be mixed with his summerdroppings, and will insure a continuance and excellent crop.These little collections of horse-droppings and road-sand, if keptdry in shed, hole, or corner, under cover, will in a short timegenerate plenty of spawn, and will be ready to be spread on thesurface of the bed in early autumn, say by the middle of Septemberor sooner. The droppings during the winter must beput into a heap, and allowed to heat gently, say up to eighty orninety degrees; then they must be turned over twice daily tolet off the heat and steam; if this is neglected the natural spawnof the droppings is destroyed. The cottager should provide[257]himself with a few barrowfuls of strawy dung to form thefoundation of his bed, so that the depth, when all is finished, benot less than a foot. Let the temperature be up to milk heat.He will then, when quite sure that the bed will not overheat, puton his summer droppings. By this time these will be one massof natural spawn, having a grey mouldy and thready appearance,and a smell like that of mushrooms. Let all be pressedvery hard; then let mould, unsifted, be put on, to the thicknessof four inches, and trodden down hard with the feet and wateredall over; and the back of a spade may now be used to make itstill harder, as well as to plaster the surface all over.”[E] Mushroomsare cultivated very extensively by Mr. Ingram, at Belvoir,without artificial spawn. There is a great riding-house there, inwhich the litter is ground down by the horses’ feet into verysmall shreds. These are placed in a heap and turned over onceor twice during the season, when a large quantity of excellentspawn is developed which, placed in asparagus beds or laid underthin turf, produces admirable mushrooms, in the latter case asclean as in our best pastures.[F]

Other species will sometimes be seen growing on mushroom-bedsbesides the genuine mushroom, the spawn in such casesbeing probably introduced with the materials employed. Wehave seen a pretty crisped variety ofAgaricus dealbatus growingin profusion in such a place, and devoured it accordingly. Sometimesthe mushrooms will, when in an unhealthy condition, besubject to the ravages of parasitic species of mould, or perhapsofHypomyces.Xylaria vaporaria has, in more than one instance,usurped the place of mushrooms. Mr. Berkeley has receivedabundant specimens in the Sclerotioid state, which he succeededin developing in sand under a bell glass. Of course under suchconditions there is much loss. The little fairy-ring champignonis an excellent and useful species, and it is a great pity thatsome effort should not be made to procure it by cultivation. In[258]Italy a kind ofPolyporus, unknown in this country, is obtainedby watering thePietra funghaia, or fungus stone, a sort of tufaimpregnated with mycelium. ThePolypori, it is said, take sevendays to come to perfection, and may be obtained from the fostermass, if properly moistened, six times a year. There are specimenswhich were fully developed in Mr. Lee’s nursery at Kensingtonmany years since. Another fungus is obtained from thepollard head of the black poplar. Dr. Badham says that it isusual to remove these heads at the latter end of autumn, as soonas the vintage is over, and their marriage with the vine isannulled; hundreds of such heads are then cut and transportedto different parts; they are abundantly watered during the firstmonth, and in a short time produce that truly delicious fungusAgaricus caudicinus, which, during the autumn of the year, makesthe greatest show in the Italian market-places. These pollardblocks continue to bear for from twelve to fourteen years.

Another fungus, which Dr. Badham himself reared (Polyporusavellanus), is procured by singeing, over a handful of straw, ablock of the cob-nut tree, which is then watered and put by.In about a month the fungi make their appearance, and arequite white, of from two to three inches in diameter, and excellentto eat, while their profusion is sometimes so great asentirely to hide the wood from whence they spring.[G] It hasbeen said thatBoletus edulis may be propagated by wateringthe ground with a watery infusion of the plants, but we have noknowledge of this method having been pursued with success.

The culture of truffles has been partially attempted, on theprinciple that, in some occult manner, certain trees producedtruffles beneath their shade. It is true that truffles are foundunder trees of special kinds, for Mr. Broome remarks that sometrees appear more favourable to the production of truffles thanothers. Oak and hornbeam are specially mentioned; but, besidesthese, chestnut, birch, box, and hazel are alluded to. Hegenerally foundTuber œstivum under beech-trees, but also underhazel,Tuber macrosporum under oaks, andTuber brumale under[259]oaks and abele. The men who collect truffles for Covent GardenMarket obtain them chiefly under beech, and in mixedplantations of fir and beech.[H]

Some notion may be obtained of the extent to which the tradeof truffles is carried in France, when we learn that in the marketof Apt alone about 3,500 pounds of truffles are exposed for saleevery week during the height of the season, and the quantitysold during the winter reaches upwards of 60,000 pounds, whilstthe Department of Vaucluse yields annually upwards of 60,000pounds. It may be interesting here to state that the value oftruffles is so great in Italy that precautions are taken againsttruffle poachers, much in the same way as against game poachersin England. They train their dogs so skilfully that, while theystand on the outside of the truffle grounds, the dogs go in anddig for the fungi. Though there are multitudes of species,they bring out those only which are of market value. Somedogs, however, are employed by botanists, which will hunt forany especial species that may be shown to them. The greatdifficulty is to prevent them devouring the truffles, of whichthey are very fond. The best dogs, indeed, are true retrievers.

The Count de Borch and M. de Bornholz give the chief accountsof the efforts that have been made towards the cultivationof these fungi. They state that a compost is prepared of puremould and vegetable soil mixed with dry leaves and sawdust, inwhich, when properly moistened, mature truffles are placed inwinter, either whole or in fragments, and that after the lapse ofsome time small truffles are found in the compost.[I] The mostsuccessful plan consists in sowing acorns over a considerableextent of land of a calcareous nature; and when the young oakshave attained the age of ten or twelve years, truffles are foundin the intervals between the trees. This process was carried onin the neighbourhood of Loudun, where truffle-beds had formerlyexisted, but where they had long ceased to be productive—a factindicating the aptitude of the soil for the purpose. In this case[260]no attempt was made to produce truffles by placing ripe specimensin the earth, but they sprang up themselves from sporesprobably contained in the soil. The young trees were leftrather wide apart, and were cut, for the first time, about thetwelfth year after sowing, and afterwards at intervals of fromseven to nine years. Truffles were thus obtained for a periodof from twenty-five to thirty years, after which the plantationsceased to be productive, owing, it was said, to the ground beingtoo much shaded by the branches of the young trees. It is theopinion of the Messrs. Tulasne that the regular cultivation ofthe truffle in gardens can never be so successful as this so-calledindirect culture at Loudun, but they think that a satisfactoryresult might be obtained in suitable soils by planting fragmentsof mature truffles in wooded localities, taking care that the otherconditions of the spots selected should be analogous to those ofthe regular truffle-grounds, and they recommend a judiciousthinning of the trees and clearing the surface from brushwood,etc., which prevents at once the beneficial effects of rain and ofthe direct sun’s rays. A truffle collector stated to Mr. Broomethat whenever a plantation of beech, or beech and fir, is made onthe chalk districts of Salisbury Plain, after the lapse of a fewyears truffles are produced, and that these plantations continueproductive for a period of from ten to fifteen years, after whichthey cease to be so.

M. Gasparin reported to the jurors of the Paris Exhibition of1855, concerning the operations of M. Rousseau, of Carpentras,on the production of oak truffles in France. The acorns of evergreenand of common oaks were sown about five yards apart.In the fourth year of the plantation three truffles were found; atthe date of the report the trees were nine years old, and over ayard in height. Sows were employed to search for the truffles.Although these plantations consist both of the evergreen andcommon oak, truffles cannot be gathered at the base of the latterspecies, it so happening that it arrives later at a state of production.The common oak, however, produces truffles like theevergreen oak, this report states, for a great number of thenatural truffle-grounds at Vaucluse are planted with common[261]oaks. It is remarked that the truffles produced from theseare larger but less regular than those of the evergreen oak,which are smaller, but nearly always spherical. The truffles aregathered at two periods of the year; in May only white trufflesare to be found, which never blacken and have no odour; theyare dried and sold for seasoning. The black truffles (Tubermelanosporum) commence forming in June, enlarging towardsthe frosty season; then they become hard, and acquire all theirperfume. They are dug a month before and a month afterChristmas. It is also asserted that truffles are produced aboutthe vine, or at any rate that the association of the vine isfavourable to the production of truffles, because truffle-plots nearvines are very productive. The observation of this decidedM. Rousseau to plant a row of vines between the oaks. Theresult of this experiment altogether does not appear to havebeen by any means flattering, for at the end of eight years onlylittle more than fifteen pounds were obtained from a hectare ofland, which, if valued at 45 francs, would leave very little profit.M. Rousseau also called attention to a meadow manured (sic)with parings of truffles, which was said to have given prodigiousresults.

The cultivation of minute fungi for scientific purposes hasbeen incidentally alluded to and illustrated in foregoing chapters,and consequently will not require such full and particular detailshere. Somewhat intermediately, we might allude to the speciesofSclerotium, which are usually compact, externally blackish,rounded or amorphous bodies, consisting of a cellular mass ofthe nature of a concentrated mycelium. Placed in favourableconditions, these forms ofSclerotium will develop the peculiarspecies of fungus belonging to them, but in certain cases theproduction is more rapid and easy than in others. In thiscountry, Mr. F. Currey has been the most successful in the cultivationofSclerotia. The method adopted is to keep them ina moist, somewhat warm, but equable atmosphere, and withpatience await the results. The well-known ergot of rye, wheat,and other grasses may be so cultivated, and Mr. Currey hasdeveloped the ergot of the common reed by keeping the stem[262]immersed in water. The final conditions are small clavate bodiesof the orderSphæriacei, belonging to the genusClaviceps. TheSclerotium of theEleocharis has been found in this country, butwe are not aware that theClaviceps developed from it has beenmet with or induced by cultivation. One method recommendedfor this sort of experiment is to fill a garden-pot half full ofcrocks, over which to place sphagnum broken up until the pot isnearly full, on this to place theSclerotia, and cover with silversand; if the pot is kept standing in a pan of water in a warmroom, it is stated that production will ensue. Ergot of thegrasses will not always develop under these conditions, butperseverance may ultimately ensure success.

A species ofSclerotium on the gills of dead Agarics originatesAgaricus tuberosus, anotherAgaricus cirrhatus,[J] but this shouldbe keptin situ when cultivated artificially, and induced todevelop whilst still attached to the rotten Agarics.Peziza tuberosa,in like manner, is developed fromSclerotia, usually foundburied in the ground in company with the roots ofAnemonenemorosa. At one time it was supposed that some relationshipexisted between the roots of the anemone and theSclerotia.From anotherSclerotium, found in the stems of bulrushes, Mr.Currey has developed a species ofPeziza, which has been namedP. Curreyana.[K] ThisPeziza has been found growing naturallyfrom theSclerotia imbedded in the tissue of common rushes.De Bary has recorded the development ofPeziza Fuckelianafrom aSclerotium of which the conidia take the form of a speciesofPolyactis.Peziza ciborioides is developed from aSclerotiumfound amongst dead leaves; and recently we have received fromthe United States an alliedPeziza which originated from theSclerotia found on the petals ofMagnolia, and which has beennamedPeziza gracilipes, Cooke, from its very slender, thread-likestem. Other species ofPeziza are also known to bedeveloped from similar bases, and these Fuckel has associated[263]together under a proposed new genus with the name ofSclerotinia.Two or three species ofTyphula, in like manner, springfrom forms ofSclerotium, long known asSclerotium complanatumandSclerotium scutellatum. Other forms ofSclerotiumare known, from one of which, found in a mushroom-bed, Mr.Currey developedXylaria vaporaria, B., by placing it on dampsand covered with a bell glass.[L] Others, again, are only knownin the sclerotioid state, such as theSclerotium stipitatum found inthe nests of white ants in South India.[M] From what is alreadyknown, however, we feel justified in the conclusion that theso-called species ofSclerotium are a sort of compact mycelium,from which, under favourable conditions, perfect fungi may bedeveloped. Mr. Berkeley succeeded in raising from the minuteSclerotium of onions, which looks like grains of coarse gunpowder,a species ofMucor. This was accomplished by placinga thin slice of theSclerotium in a drop of water under a glassslide, surrounded by a pellicle of air, and luted to preventevaporation and external influences.[N]

As to the cultivation of moulds andMucors, one great difficultyhas to be encountered in the presence or introduction offoreign spores to the matrix employed for their development.Bearing this in mind, extensive cultivations may be made, butthe conditions must influence the decision upon the results.Rice paste has been used with advantage for sowing the sporesof moulds, afterwards keeping them covered from external influences.In cultivation on rice paste of rare species, theexperimenter is often perplexed by the more rapid growth ofthe common species ofMucor andPenicillium. Mr. Berkeleysucceeded in developing up to a certain point the fungus of theMadura Foot, but though perfect sporangia were produced, thefurther development was masked by the outgrowth of otherspecies. In like manner, orange juice, cut surfaces of fruits,[264]slices of potato tubers, etc., have been employed. Fresh, horse-dung,placed under a bell glass and kept in a humid atmosphere,will soon be covered withMucor, and in like manner the growthof common moulds upon decayed fruit may be watched; but thiscan hardly be termed cultivation unless the spores of some individualspecies are sown. Different solutions have been proposedfor the growth of such conditions as the cells which induce fermentation,to which yeast plants belong. A fly attacked byEmpusa muscæ, if immersed in water, will develop one of theSaprolegniæ.

TheUredines and other epiphyllousConiomycetes will readilygerminate by placing the leaf which bears them on damp sand,or keeping them in a humid atmosphere. Messrs. Tulasne andDe Bary have, in their numerous memoirs, detailed the methodsadopted by them for different species, both for germination ofthe pseudospores and for impregnating healthy foster plants.The germination of the pseudospores of the species ofPodisomamay easily be induced, and secondary fruits obtained. Thegermination of the spores ofTilletia is more difficult to accomplish,but this may be achieved. Mr. Berkeley found no difficulty,and had the stem impregnated as well as the germen. On theother hand, the pseudospores ofCystopus, when sown in wateron a slip of glass, will soon produce the curious little zoosporesin the manner already described.

The sporidia of theDiscomycetes, and some of theSphæriacei,germinate readily in a drop of water on a slip of glass, althoughnot proceeding further than the protrusion of germ-tubes. Aform of slide has been devised for growing purposes, in whichthe large covering glass is held in position, and one end of theslip being kept immersed in a vessel of water, capillary attractionkeeps up the supply for an indefinite period, so that there isno fear of a check from the evaporation of the fluid. Even whensaccharine solutions are employed this method may be adopted.

The special cultivation of thePeronosporei occupied the attentionof Professor De Bary for a long time, and his experiencesare detailed in his memoir on that group,[O] but which are too[265]long for quotation here, except his observations on the developmentof the threads ofPeronospora infestans on the cut surfaceof the tubers of diseased potatoes. When a diseased potato iscut and sheltered from dessication, the surface of the slice coversitself with the mycelium and conidiiferous branches ofPeronospora,and it can easily be proved that these organs originatefrom the intercellulary tubes of the brown tissue. The myceliumthat is developed upon these slices is ordinarily very vigorous;it often constitutes a cottony mass of a thickness of many millimetres,and it gives out conidiiferous branches, often partitioned,and larger and more branched than those observed on the leaves.The appearance of these fertile branches ordinarily takes placeat the end of from twenty-four to forty-eight hours; sometimes,nevertheless, one must wait for many days. These phenomenaare observed in all the diseased tubercles without exception, solong as they have not succumbed to putrefaction, which arreststhe development of the parasite and kills it.

Young plants of the species liable to attack may be inoculatedwith the conidia of the species ofPeronospora usually developedon that particular host, in the same manner that young cruciferousplants, watered with an infusion of the spores ofCystopuscandidus, will soon exhibit evidence of attack from the whiterust.

It is to the cultivation and close investigation of the growthand metamorphoses of the minute fungi that we must look forthe most important additions which have yet to be made to ourknowledge of the life-history of these most complex and interestingorganisms.

Unfortunately no complete or satisfactory account can be givenof the geographical distribution of fungi. The younger Fries,[A]with all the facilities at his disposal which the lengthenedexperience and large collections of his father afforded, could onlygive a very imperfect outline, and now we can add very littleto what he has given. The cause of this difficulty lies in thefact that the Mycologic Flora of so large a portion of the worldremains unexplored, not only in remote regions, but even incivilized countries where the Phanerogamic Flora is well known.Europe, England, Scotland, and Wales are as well explored asany other country, but Ireland is comparatively unknown, nocomplete collection having ever been made, or any at leastpublished. Scandinavia has also been well examined, and thenorthern portions of France, with Belgium, some parts of Germanyand Austria, in Russia the neighbourhood of St. Petersburg,and parts of Italy and Switzerland. Turkey in Europe,nearly all Russia, Spain, and Portugal are almost unknown. Asto North America, considerable advances have been made sinceSchweinitz by Messrs. Curtis and Ravenel, but their collectionsin Carolina cannot be supposed to represent the whole of theUnited States; the small collections made in Texas, Mexico,etc., only serve to show the richness of the country, not yet halfexhausted. It is to be hoped that the young race of botanistsin the United States will apply themselves to the task of investigating[267]the Mycologic Flora of this rich and fertile region. InCentral America very small and incomplete collections have asyet been made, and the same may be said of South America andCanada. Of the whole extent of the New World, only theCarolina States of North America can really be said to be satisfactorilyknown. Asia is still less known, the whole of our vastIndian Empire being represented by the collections made byDr. Hooker in the Sikkim Himalayas, and a few isolated specimensfrom other parts. Ceylon has recently been removed fromthe category of the unknown by the publication of its MycologicFlora.[B] All that is known of Java is supplied by the researchesof Junghuhn; whilst all the rest is completely unknown, includingChina, Japan, Siam, the Malayan Peninsula, Burmah, andthe whole of the countries in the north and west of India. Alittle is known of the Philippines, and the Indian Archipelago,but this knowledge is too fragmentary to be of much service.In Africa no part has been properly explored, with the exceptionof Algeria, although something is known of the Cape of GoodHope and Natal. The Australasian Islands are better representedin the Floras published of those regions. Cuba and theWest Indies generally are moderately well known from thecollections of Mr. C. Wright, which have been recorded in thejournal of the Linnæan Society, and in the same journal Mr.Berkeley has described many Australian species.

It will be seen from the above summary how unsatisfactoryit must be to give anything like a general view of the geographicaldistribution of fungi, or to estimate at all approximatelythe number of species on the globe. Any attempt, therefore,must be made and accepted subject to the limitations we haveexpressed.

The conditions which determine the distribution of fungi arenot precisely those which determine the distribution of thehigher plants. In the case of the parasitic species they may besaid to follow the distribution of their foster-plants, as in thecase of the rust, smut, and mildew of the cultivated cereals,[268]which have followed those grains wherever they have beendistributed, and the potato disease, which is said to have beenknown in the native region of the potato plant before it madeits appearance in Europe. We might also allude toPucciniamalvacearum, Ca., which was first made known as a SouthAmerican species; it then travelled to Australia, and at lengthto Europe, reaching England the next year after it was recordedon the Continent. In the same manner, so far as we have themeans of knowing,Puccinia Apii, Ca., was known on the Continentof Europe for some time before it was detected on thecelery plants in this country. Experience seems to warrant theconclusion that if a parasite affects a certain plant withina definite area, it will extend in time beyond that area toother countries where the foster-plant is found. This viewaccounts in some part for the discovery of species in this country,year after year, which had not been recorded before; someallowance being made for the fact that an increased number ofobservers and collectors may cause the search to be more complete,yet it must be conceded that the migration of Continentalspecies must to some extent be going on, or how can it beaccounted for that such large and attractive fungi asSparassiscrispa,Helvellas gigas, andMorchella crassipes had never beenrecorded till recently, or amongst parasitic species such as thetwo species ofPuccinia above named? In the same manner itis undoubtedly true that species which at one time were commongradually become somewhat rare, and at length nearly extinct.We have observed this to apply to the larger species as well asto the microscopic in definite localities. For instance,Craterelluscornucopioides some ten years ago appeared in one wood,at a certain spot, by hundreds, whereas during the past three orfour years we have failed to find a single specimen. As manyyears since, and in two places, where the goat’s-beard was abundant,as it is now, we found nearly half the flowering headsinfested withUstilago receptaculorum, but for the past two orthree years, although we have sought it industriously, not asingle specimen could be found. It is certain that plants foundby Dickson, Bolton, and Sowerby, have not been detected since,[269]whilst it is not improbable that species common with us may bevery rare fifty years hence. In this manner it would reallyappear that fungi are much more liable than flowering plants toshift their localities, or increase and diminish in number.

The fleshy fungi,Agaricini andBoleti especially, are largelydependent upon the character of woods and forests. When theundergrowth of a wood is cleared away, as it often is every fewyears, it is easy to observe a considerable difference in the fungi.Species seem to change places, common ones amongst a denseundergrowth are rare or disappear with the copsewood, andothers not observed before take their place. Some species, too,are peculiar to certain woods, such as beech woods and fir woods,and their distribution will consequently depend very muchon the presence or absence of such woods. Epiphytal species,such asAgaricus ulmarius,Agaricus mucidus, and a host ofothers, depend on circumstances which do not influence thedistribution of flowering plants. It may be assumed thatsuch species as flourish in pastures and open places are subjectto fewer adverse conditions than those which affect woods andforests.

Any one who has observed any locality with reference to itsMycologic Flora over a period of years will have been struckwith the difference in number and variety caused by what maybe termed a “favourable season,” that is, plenty of moisture inAugust with warm weather afterwards. Although we know butlittle of the conditions of germination in Agarics, it is butreasonable to suppose that a succession of dry seasons will considerablyinfluence the flora of any locality. Heat and humidity,therefore, are intimately concerned in the mycologic vegetationof a country. Fries has noted in his essay the features to whichwe have alluded. “The fact,” he says, “must not be lost sightof that some species of fungi which have formerly been commonin certain localities may become, within our lifetime, more andmore scarce, and even altogether cease to grow there. Thecause of this, doubtless, is the occurrence of some change in thephysical constitution of a locality, such as that resulting fromthe destruction of a forest, or from the drainage, by ditches and[270]cuttings, of more or less extensive swamps, or from the cultivationof the soil—all of them circumstances which cause thedestruction of the primitive fungaceous vegetation and the productionof a new one. If we compare the fungal flora of Americawith that of European countries, we observe that the formerequals, in its richness and the variety of its forms, that of thephanerogamous flora; it is probable, however, that, in thelapse of more or fewer years, this richness will decrease, inconsequence of the extension of cultivation—as is illustrated,indeed, in what has already taken place in the more thicklypeopled districts, as, for example, in the vicinity of NewYork.”

Although heat and humidity influence all kinds of vegetation,yet heat seems to exert a less, and humidity a greater, influenceon fungi than on other plants. It is chiefly during the coolmoist autumnal weather that the fleshy fungi flourish mostvigorously in our own country, and we observe their number toincrease with the humidity of the season. Rain falls copiouslyin the United States, and this is one of the most fruitful countriesknown for the fleshy fungi. Hence it is a reasonablededuction that moisture is a condition favourable to the developmentof these plants. TheMyxogastres, according to Dr. HenryCarter, are exceedingly abundant—in individuals, at least, if notin species—in Bombay, and this would lead to the conclusionthat the members of this group are influenced as much by heatas humidity in their development, borne out by the more plentifulappearance of the species in this country in the warmerweather of summer.

In the essay to which we have alluded, Fries only attemptsthe recognition of two zones in his estimate of the distributionof fungi, and these are the temperate and tropical. The frigidzone produces no peculiar types, and is poor in the number ofspecies, whilst no essential distinction can be drawn between thetropical and sub-tropical with our present limited information.Even these two zones must not be accepted too rigidly, sincetropical forms will in some instances, and under favourable conditions,extend far upwards into the temperate zone.

“In any region whatever,” writes Fries, “it is necessary, inthe first instance, to draw a distinction between its open nakedplains and its wooded tracts. In the level open country there isa more rapid evaporation of the moisture by the conjoined actionof the sun and wind; whence it happens that such a region ismore bare of fungi than one that is mountainous or covered bywoods. On the other hand, plains possess several species peculiarto themselves; as, for example,Agaricus pediades, certainTricholomata, and, above all, the familyCoprini, of which theymay be regarded as the special habitat. The species of thisfamily augment in number, in any given country, in proportionto the extent and degree of its cultivation; for instance, theygrow more luxuriantly in the province of Scania, in Sweden—adistrict farther distinguished above all others by its cultivationand fertility. In well-wooded countries moisture is retained amuch longer time, and, as a result, the production of fungi isincomparably greater; and it is here desirable to make a distinctionbetween the fungi growing in forests of resinous-woodedtrees (Coniferæ) and those which inhabit woods of other trees,for these two descriptions of forests may be rightly regarded, asto their fungaceous growths, as two different regions. Beneaththe shade ofConiferæ, fungi are earlier in their appearance; somuch so, that it often happens they have attained their full developmentwhen their congeners in forests of non-resinous treeshave scarcely commenced their growth. In woods of the lattersort, the fallen leaves, collected in thick layers, act as an obstacleto the soaking of moisture into the earth, and thereby retardthe vegetation of fungi; on the other hand, such woods retainmoisture longer. These conditions afford to several large andremarkable species the necessary time for development. Thebeech is characteristic of our own region, but, further north thistree gives place to the birch. Coniferous woods are, moreover,divisible into two regions—that of the pines and that of the firs.The latter is richer in species than the former, because, as iswell known, fir-trees flourish in more fertile and moister soils.Whether, with respect to the South of Europe, other subdivisionsinto regions are required, we know not; still less are[272]we able to decide on the like question in reference to the countriesbeyond Europe.”[C]

In very cold countries the higher fungi are rare, whilst intropical countries they are most common at elevations whichsecure a temperate climate. In Java, Junghuhn found themmost prolific at an elevation of 3,000 to 5,000 feet; and inIndia, Dr. Hooker remarked that they were most abundant atan elevation of 7,000 to 8,000 feet above the sea level.

For the higher fungi we must be indebted to the summarymade by Fries, to which we have little to add.

The genusAgaricus occupies the first place, and surpasses, inthe number of species, all the other generic groups known. Itappears, from our present knowledge, that theAgarici have theirgeographic centre in the temperate zone, and especially in thecolder portion of that zone. It is a curious circumstance thatall the extra-European species of this genusAgaricus may bereferred to various European subgenera.

In tropical countries it appears that theAgarici occupy only asecondary position in relation to other genera of fungi, such asPolyporus,Lenzites, etc. North America, on the other hand, isricher in species ofAgaricus than Europe; for whilst the majorityof typical forms are common to both continents, Americafurther possesses many species peculiar to itself. In the temperatezone, so close is the analogy prevailing between thevarious countries in respect to theAgaricini, that from Swedento Italy, and as well in England as North America, the samespecies are to be found. Of 500Agaricini met with in St.Petersburg, there are only two or three which have not beendiscovered in Sweden; and again, of fifty species known inGreenland, there is not one that is not common in Sweden. Thesame remarks hold good in reference to theAgaricini of Siberia,Kamtschatka, the Ukraine, etc. The countries bordering uponthe Mediterranean possess, however, several peculiar types; andEastern and Western Europe present certain dissimilarities intheir Agaric inhabitants. Several species, for example, ofArmillaria[273]andTricholoma, which have been found in Russia, havebeen met with in Sweden only in Upland, that is, in the mosteastern province; all the species which belong to the so-calledabiegno-rupestres andpineto-montanæ regions of Sweden arewanting in England; and it is only in Scotland that the speciesof northern mountainous and pine-bearing regions are met with—acircumstance explicable from the similarity in physical featuresbetween Sweden and the northern portions of Great Britain.

The species ofCoprinus appear to find suitable habitats inevery quarter of the globe.

TheCortinariæ predominate in the north; they abound inNorthern latitudes, especially on wooded hills; but the plains offeralso some peculiar species which flourish during the rainy daysof August and September. In less cold countries they are morescarce or entirely absent. The species of the genusHygrophoruswould at first seem to have a similar geographical distributionto those of the last group; but this is really not the case, forthe sameHygrophori are to be found in nearly every country ofEurope, and even the hottest countries (and those under theequator) are not destitute of representatives of this wide-spreadgenus.

TheLactarii, which are so abundant in the forests of Europeand North America, appear to grow more and more scarcetowards both the south and north. The same may be statedin regard toRussula.

The genusMarasmius is dispersed throughout the globe, andeverywhere presents numerous species. In inter-tropical countriesthey are still more abundant, and exhibit peculiarities ingrowth which probably might justify their collection into adistinct group.

The generaLentinus andLenzites are found in every regionof the world; their principal centre, however, is in hot countries,where they attain a splendid development. On the contrary,towards the north they rapidly decrease in number.

ThePolypori constitute a group which, unlike that of theAgarics, especially belongs to hot countries. TheBoleti constitutethe only exception to this rule, since they select the[274]temperate and frigid zones for their special abode, and some ofthem at times find their way to the higher regions of the Alps.No one can describe the luxuriance of the torrid zone inPolyporiandTrametes, genera ofHymenomycetes, which flourishbeneath the shade of the virgin forests, where perpetual moistureand heat promote their vegetation and give rise to an infinitevariety of forms. But though the genusPolyporus, which rivalsAgaricus in the number of its species, inhabits, in preference,warm climates at large, it nevertheless exhibits species peculiarto each country. This arises from the circumstance that thePolypori, for the most part, live upon trees, and are dependenton this or that particular tree for a suitable habitat; and thetropical flora being prolific in trees of all kinds, a multitude ofthe most varied forms of these fungi is a necessary consequence.Hexagona,Favolus, andLaschia are common in inter-tropicalcountries, but they are either entirely absent or extremely rarein temperate climes.

When the majority of the species of a genus are of a fleshyconsistence, it may generally be concluded that that genusbelongs to a Northern region, even if it should have some representativesin lands which enjoy more sunshine. Thus theHydnaare the principal ornaments of Northern forests, where they attainso luxuriant a growth and beauty that every other country mustyield the palm to Sweden in respect to them. In an allied genus,that ofIrpex, the texture assumes a coriaceous consistence, andwe find its species to be more especially inhabitants of warmclimates.

Most of the genera ofAuricularini are cosmopolitan, and thesame is true of some species ofStereum, ofCorticium, etc., whichare met with in countries of the most different geographicalposition. In tropical countries, these genera of fungi assume themost curious and luxuriant forms. The single and not considerablegenusCyphella appears to be pretty uniformly distributedover the globe. TheClavariæi are equally universal in theirdiffusion, although more plentiful in the north; however, thegenusPterula possesses several exotic forms, though in Europeit has but two representative species. That beautiful genus of[275]Hymenomycetes,Sparassis, occupies a similar place next theClavariæi, and is peculiarly a production of the temperate zoneand of the coniferous region.

The fungi which constitute the family ofTremellini prevail inEurope, Asia, and North America, and exhibit no marked differencesamongst themselves, notwithstanding the distances of theseveral countries apart. It must, however, be stated that theHirneolæ for the most part inhabit the tropics.

We come now to theGasteromycetes—an interesting family,which exhibits several ramifications or particular series of developments.The most perfectGasteromycetes almost exclusivelybelong to the warmer division of the temperate, and to thetropical zone, where their vegetation is the most luxuriant. Oflate the catalogue of these fungi has been greatly enriched bythe addition of numerous genera and species, proper to hot countries,previously unknown. Not uncommonly, the exotic florasdiffer from ours, not merely in respect of the species, but also ofthe genera ofGasteromycetes. It must, besides, be observedthat this family is rich in well-defined genera, though very poorin distinct specific forms. Among the genera found in Europe,many are cosmopolitan.

ThePhalloidei present themselves in the torrid zone underthe most varied form and colouring, and comprise many generarich in species. In Europe their number is very restricted. Aswe advance northward they decrease rapidly, so that the centraldistricts of Sweden possess only a single species, thePhallusimpudicus, and even this solitary representative of the family isvery scarce. In Scania, the most southern province of Sweden,there is likewise but one genus and one species belonging to it,viz., theMutinus caninus. Among other members of thePhalloidei,may be further mentioned theLysurus of China, theAseröe of Van Diemen’s Land, and theClathrus, one species ofwhich,C. cancellatus, has a very wide geographical range; forinstance, it is found in the south of Europe, in Germany, and inAmerica; it occurs also in the south of England and the Isle ofWight; whereas the other species of this genus have a verylimited distribution.

TheTuberacei[D] are remarkable amongst the fungi in beingall of them more or less hypogeous. They are natives of warmcountries, and are distributed into numerous genera and species.TheTuberacei constitute in Northern latitudes a group of fungivery poor in specific forms. The few species of theHymenogastresbelonging to Sweden, with the exception ofHyperrhizavariegata and one example of the genusOctaviana, are confinedto the southern provinces. The greater part of this group, liketheLycoperdacei, are met with in the temperate zone. Mostexamples of the genusLycoperdon are cosmopolitan.

TheNidulariacei and theTrichodermacei appear to be scatteredover the globe in a uniform manner, although their speciesare not everywhere similar. The same statement applies to theMyxogastres, which are common in Lapland, and appear to havetheir central point of distribution in the countries within thetemperate zone. At the same time, they are not wanting intropical regions, notwithstanding that the intensity of heat, bydrying up the mucilage which serves as the medium for thedevelopment of their spores, is opposed to their development.[E]

Of theConiomycetes, the parasitic species, as theCæomacei, thePucciniei, and theUstilagines, accompany their foster-plants intoalmost all regions where they are found; so that smut, rust, andmildew are as common on wheat and barley in the Himalayasand in New Zealand as in Europe and America.Ravenelia andCronartium only occur in the warmer parts of the temperatezone, whilstSartvellia is confined to Surinam. Species ofPodisoma andRœstelia are as common in the United States asin Europe, and the latter appears also at the Cape and Ceylon.Wherever species ofSphæria occur there theSphæronemei arefound, but they do not appear, according to our present knowledge,to be so plentiful in tropical as in temperate countries.TheTorulacei and its allies are widely diffused, and probablyoccur to a considerable extent in tropical countries.

Hyphomycetes are widely diffused; some species are peculiarly[277]cosmopolitan, and all seem to be less influenced by climaticconditions than the more fleshy fungi. TheSepedoniei arerepresented by at least one species whereverBoletus is found.TheMucedines occur everywhere in temperate and tropicalregions,Penicillium andAspergillus flourishing as much in thelatter as in the former.Botrytis andPeronospora are almost aswidely diffused and as destructive in warmer as in temperatecountries, and although from difficulty in preservation the mouldsare seldom represented to any extent in collections, yet indicationsof their presence constantly occur in connection with otherforms, to such an extent as to warrant the conclusion that theyare far from uncommon. TheDematiei are probably equally aswidely diffused. Species ofHelminthosporium,Cladosporium,andMacrosporium seem to be as common in tropical as temperateclimes. The distribution of these fungi is imperfectly known,except in Europe and North America, but their occurrence inCeylon, Cuba, India, and Australasia indicated a cosmopolitanrange.Cladosporium herbarum would seem to occur everywhere.TheStilbacei andIsariacei are not less widely diffused, althoughas yet apparently limited in species.Isaria occurs on insectsin Brazil as in North America, and species ofStilbum andIsariaare by no means rare in Ceylon.

ThePhysomycetes have representatives in the tropics, speciesofMucor occurring in Cuba, Brazil, and the southern states ofNorth America, with the same and allied genera in Ceylon.Antennaria andPisomyxa seem to reach their highest developmentin hot countries.

TheAscomycetes are represented everywhere, and althoughcertain groups are more tropical than others, they are representedin all collections. The fleshy forms are most prolific in temperatecountries, and only a few species ofPeziza affect the tropics,yet in elevated districts of hot countries, such as the Himalayasof India,Peziza,Morchella, andGeoglossum are found. Two orthree species ofMorchella are found in Kashmir, and at leastone or two in Java, where they are used as food. The genusCyttaria is confined to the southern parts of South Americaand Tasmania. The United States equal if they do not exceed[278]European states in the number of species of theDiscomycetes.ThePhacidiacei are not confined to temperate regions, but aremore rare elsewhere.Cordierites andAcroseyphus (?) are tropicalgenera, the former extending upwards far into the temperatezone, asHysterium andRhytisma descend into the tropics.Amongst theSphæriacei,Xylaria andHypoxylon are well representedin the tropics, such species asXylaria hypoxylon andXylaria corniformis being widely diffused. In West Africa anAmerican species ofHypoxylon is amongst the very few specimensthat have ever reached us from the Congo, whilstH. concentricum andUstulina vulgaris seem to be almost cosmopolitan.Torrubia andNectria extend into the tropics, but aremore plentiful in temperate and sub-tropical countries.Dothideais well represented in the tropics, whilst of the species ofSphæria proper, only the more prominent have probably beensecured by collectors; hence theSuperficiales section is betterrepresented than theObtectæ, and the tropical representativesof foliicolous species are but few.Asterina,Micropeltis, andPemphidium are more sub-tropical than temperate forms. ThePerisporiacei are represented almost everywhere; althoughspecies ofErysiphe are confined to temperate regions, the genusMeliola occupies its place in warmer climes. Finally, theTuberacei, which are subterranean in their habits, are limitedin distribution, being confined to the temperate zone, neverextending far into the cold, and but poorly represented out ofEurope. One species ofMylitta occurs in Australia, anotherin China, and another in the Neilgherries of India; the genusPaurocotylis is found in New Zealand and Ceylon. It is saidthat a species ofTuber is found in Himalayan regions, but inthe United States, as well as in Northern Europe, theTuberaceiare rare.

The imperfect condition of our information concerning verymany countries, even of those partially explored, must renderany estimate or comparison of the floras of those countries mostfragmentary and imperfect. Recently, the mycology of our ownislands has been more closely investigated, and the result ofmany years’ application on the part of a few individuals has[279]appeared in a record of some 2,809 species,[F] to which subsequentadditions have been made, to an extent of probably not muchless than 200 species,[G] which would bring the total to about3,000 species. The result is that no material difference existsbetween our flora and that of Northern France, Belgium, andScandinavia, except that in the latter there are a larger numberof Hymenomycetal forms. The latest estimates of the flora ofScandinavia are contained in the works of the illustrious Fries,[H]but these are not sufficiently recent, except so far as regardstheHymenomycetes, for comparison of numbers with Britishspecies.

The flora of Belgium has its most recent exponent in the posthumouswork of Jean Kickx; but the 1,370 species enumeratedby him can hardly be supposed to represent the whole of thefungi of Belgium, for in such case it would be less than half thenumber found in the British Islands, although the majority ofgenera and species are the same.[I]

For the North of France no one could have furnished amore complete list, especially of the microscopic forms, thanM. Desmazières, but we are left to rely solely upon his papers in“Annales des Sc. Nat.” and his published specimens, which,though by no means representative of the fleshy fungi, are doubtlesstolerably exhaustive of the minute species. From what weknow of FrenchHymenomycetes, their number and varietyappear to be much below those of Great Britain.[J]

The mycologic flora of Switzerland has been very well investigated,[280]although requiring revision. Less attention having beengiven to the minute forms, and more to theHymenomycetes thanin France and Belgium, may in part account for the larger proportionof the latter in the Swiss flora.[K]

In Spain and Portugal scarce anything has been done; thesmall collection made by Welwitsch can in no way be supposedto represent the Peninsula.

The fungi of Italy[L] include some species peculiar to thePeninsula. TheTuberacei are well represented, and althoughtheHymenomycetes do not equal in number those of Britain orScandinavia, a good proportion is maintained.

Bavaria and Austria (including Hungary, and the Tyrol) arebeing more thoroughly investigated than hitherto, but the worksof Schæffer, Tratinnick, Corda, and Krombholz have made usacquainted with the general features of their mycology,[M] towhich more recent lists and catalogues have contributed.[N] Thepublication of dried specimens has of late years greatly facilitatedacquaintance with the fungi of different countries inEurope, and those issued by Baron Thümen from Austria do notdiffer materially from those of Northern Germany, althoughDr. Rehm has made us acquainted with some new and interestingforms from Bavaria.[O]

Russia is to a large extent unknown, except in its northernborders.[P] Karsten has investigated the fungi of Finland,[Q] and[281]added considerably to the number ofDiscomycetes, for whichthe climate seems to be favourable; but, as a whole, it may beconcluded that Western and Northern Europe are much betterexplored than the Eastern and South-Eastern, to which we mightadd the South, if Italy be excepted.

We have only to add, for Europe, that different portions ofthe German empire have been well worked, from the period ofWallroth to the present.[R] Recently, the valley of the Rhine hasbeen exhaustively examined by Fuckel;[S] but both Germany andFrance suffered checks during the late war which made theirmark on the records of science not so speedily to be effaced.Denmark, with its splendid Flora Danica still in progress, morethan a century after its commencement,[T] has a mycologic floravery like to that of Scandinavia, which is as well known.

If we pass from Europe to North America, we find there amycologic flora greatly resembling that of Europe, and althoughCanada and the extreme North is little known, some parts ofthe United States have been investigated. Schweinitz[U] firstmade known to any extent the riches of this country, especiallyCarolina, and in this state the late Dr. Curtis and H. W. Ravenelcontinued their labours. With the exception of Lea’s collectionsin Cincinnati, Wright’s in Texas, and some contributions fromOhio, Alabama, Massachusetts, and New York, a great portionof this vast country is mycologically unknown. It is remarkablyrich in fleshy fungi, not only inAgaricini, but also inDiscomycetes,containing a large number of European forms, mostly[282]European genera, with many species at present peculiar to itself.Tropical forms extend upwards into the Southern States.

The islands of the West Indies have been more or less examined,but none so thoroughly as Cuba, at first by Ramon de laSagra, and afterwards by Wright.[V] The three principal generaofHymenomycetes represented areAgaricus,Marasmius, andPolyporus, represented severally by 82, 51, and 120 species,amounting to more than half the entire number. Of the 490species, about 57 per cent. are peculiar to the island; 13 percent. are widely dispersed species; 12 per cent. are common tothe island and Central America, together with the warmer partsof South America and Mexico; 3 per cent. are common to itwith the United States, especially the Southern; while 13 percent. are European species, including, however, 13 which maybe considered as cosmopolitan. Some common tropical speciesdo not occur, and, on the whole, the general character seemssub-tropical rather than tropical. Many of the species aredecidedly those of temperate regions, or at least nearly allied.Perhaps the most interesting species are those which occur inthe generaCraterellus andLaschia, the latter genus, especially,yielding several new forms. The fact that the climate is, on thewhole, more temperate than that of some other islands in thesame latitudes, would lead us to expect the presence of a comparativelylarge number of European species, or those whichare found in the more northern United States, or British NorthAmerica, and may account for the fact that so small a proportionof species should be identical with those from neighbouringislands.

In Central America only a few small collections have beenmade, which indicate a sub-tropical region.

From the northern parts of South America, M. Leprieurcollected in French Guiana.[W] Southwards of this, Spruce collectedin the countries bordering on the River Amazon, and[283]Gardner in Brazil,[X] Gaudichaud in Chili and Peru,[Y] Gay inChili,[Z] Blanchet in Bahia,[a] Weddell in Brazil,[b] and Augustede Saint Hiliare[c] in the same country. Small collections havealso been made in the extreme south. All these collectionscontain coriaceous species ofPolyporus,Favolus, and alliedgenera, withAuricularini, together with suchAscomycetes asXylaria, and such forms ofPeziza asP. tricholoma,P. Hindsii,andP. macrotis. As yet we cannot form an estimate of theextent or variety of the South American flora, which has furnishedthe interesting genusCyttaria, and may yet supply formsunrecognized elsewhere.

The island of Juan Fernandez furnished to M. Bertero a goodrepresentative collection,[d] which is remarkable as containingmore than one-half its number of European species, and the restpossessing rather the character of those of a temperate than asub-tropical region.

Australasia has been partly explored, and the results embodiedin the Floras of Dr. Hooker and subsequent communications.In a note to an enumeration of 235 species in 1872, the writerobserves that “many of them are either identical with Europeanspecies, or so nearly allied that with dried specimens only,unaccompanied by notes or drawings, it is impossible to separatethem; others are species which are almost universally found intropical or sub-tropical countries, while a few only are peculiarto Australia, or are undescribed species, mostly of a tropical type.The collections on the whole can scarcely be said to be of anygreat interest, except so far as geographical distribution is concerned,as the aberrant forms are few.”[e]

The fungi collected by the Antarctic Expedition in Aucklandand Campbell’s Islands, and in Fuegia and the Falklands,[f] werefew and of but little interest, including such cosmopolitanforms asSphæria herbarum andCladosporium herbarum,Hirneolaauricula-judæ,Polyporus versicolor,Eurotium herbariorum, etc.

In New Zealand a large proportion have been found, and thesemay be taken to represent the general character of the fungiof the islands, which is of the type usually found in temperateregions.[g]

The fungi of Asia are so little known that no satisfactoryconclusions can be drawn from our present incomplete knowledge.In India, the collections made by Dr. Hooker in hisprogress to the Sikkim Himalayas,[h] a few species obtained byM. Perottet in Pondicherry, and small collections from theNeilgherries,[i] are almost all that have been recorded. Fromthese it may be concluded that elevations such as approximatea temperate climate are the most productive, and here Europeanand North American genera, with closely allied species, havethe preponderance. The number ofAgaricini, for instance, islarge, and amongst the twenty-eight subgenera into which thegenusAgaricus is divided, eight only are unrepresented. Casualspecimens received from other parts of India afford evidencethat here is a vast field unexplored, the forests and mountainslopes of which would doubtless afford an immense number ofnew and interesting forms.

Of the Indian Archipelago, Java has been most explored, bothby Junghuhn[j] and Zollinger.[k] The former records 117 speciesin 40 genera, Nees von Esenbeck and Blume 11 species in3 genera, and Zollinger and Moritzi 31 species in 20 genera,making a total of 159 species, of which 47 belong toPolyporus.[285]Léveillé added 87 species, making a total of 246 species. Thefungi of Sumatra, Borneo, and other islands are partly the sameand partly allied, but of a similar tropical character.

The fungi of the island of Ceylon, collected by Gardner,Thwaites, and König, were numerous. The Agarics comprise302 species, closely resembling those of our own country.[l] Itis singular that every one of the subgenera of Fries is represented,though the number of species in one or two is greatlypredominant.Lepiota andPsalliota alone comprise one-thirdof the species, whilePholiota offers only a single obscure species.The enumeration recently published of the succeeding familiescontains many species of interest.

In Africa, the best explored country is Algeria, althoughunfortunately the flora was never completed.[m] The correspondencebetween the fungi of Algeria and European countries isvery striking, and the impression is not removed by the presenceof a few sub-tropical forms. It is probable that were the fungiof Spain known the resemblance would be more complete.

From the Cape of Good Hope and Natal collections have beenmade by Zeyher,[n] Drége, and others, and from these we areenabled to form a tolerable estimate of the mycologic flora. OftheHymenomycetes, the greater part belong toAgaricus: thereare but four or fivePolypori in Zeyher’s collection, one of whichis protean. TheGasteromycetes are interesting, belonging tomany genera, and presenting two,Scoleciocarpus andPhellorinia,which were founded upon specimens in this collection.Batarrea,Tulostoma, andMycenastrum are represented by European species.There are also two species ofLycoperdon, and one ofPodaxon.Besides these, there is the curiousSecotium Gueinzii. The genusGeaster does not appear in the collection, norScleroderma.Altogether the Cape flora is a peculiar one, and can scarcely becompared with any other.

At the most, only scattered and isolated specimens have been[286]recorded from Senegal, from Egypt, or from other parts ofAfrica, so that, with the above exceptions, the continent maybe regarded as unknown.

From this imperfect summary it will be seen that no generalscheme of geographical distribution of fungi can as yet beattempted, and the most we can hope to do is to comparecollection with collection, and what we know of one countrywith what we know of another, and note differences and agreements,so as to estimate the probable character of the fungi ofother countries of which we are still in ignorance. It is wellsometimes that we should attempt a task like the present, sincewe then learn how much there is to be known, and how muchgood work lies waiting to be done by the capable and willinghands that may hereafter undertake it.