The observed infall of galaxies in the Virgo Southern Extension toward the Virgo Cluster is characterized by a family of mass models satisfying the requirement of an explanation of the Milky Way's motion with respect to the Virgo Cluster, in order to furnish constraints of cosmological interest. If the age of the universe is 10-15 Gyr, there is a rough coincidence of the mass required to explain the infall pattern of galaxies near the cluster, the mass needed to account for the motion of the Milky Way, and the mass implied for the central cluster by the virial theorem, in which case most of the supercluster's mass must reside in the Virgo Cluster. With the mass-age models and a census of the distribution of galaxies near the Virgo Cluster, it is possible to estimate the near-future accretion rate of galaxies into the central cluster.