328 IVORY AND THE ELEPHANT
chain of development from the earliest elephant species clearly defined in the remains, the Elephas planifrons, a type prevailing in the Upper Pliocene. From this earliest variety—the existence of a still earlier Elephas priscus has not been clearly established—there were evolved, during the Upper Pliocene, two Indian forms, the Elephas hysudricus in the east and the Elephas meridionalis in the west. It is from this latter species, or from some of the intermediate forms between it and E. planifrons that,
in the Pleistocene period, the European species are derived. As a
result of the long-continued migrations and of the consequent changes
brought about in a long lapse of time by varied climatic and geographic
conditions, two main types were evolved in Europe, one inhabiting
principally the woods and forests, the Elephas antiquus, and the other the plains and open valleys, the Elephas primigenius.
The
origin of the dwarf-elephant species, of which fossil remains have been
found in some Mediterranean islands, is believed by Soergel to have
resulted from a progressive degeneration of the full-grown type, owing
to the imperfect environment provided by the restricted island
territory. This, however, scarcely seems to account for the living
dwarf elephants of the Congo region in Africa. Thus, in the case of the
extinct Elephas melitensis, we would have a degenerated E. antiquus, while the Elephas cypriotis, of
the Island of Cyprus, presents certain features indicating that it was
derived from an earlier form of the European elephant, one more closely
allied to E. meridionalis.
In the Pleistocene age the species E. hysudricus gave rise in process of time to the later species Elephas indicus, the immediate ancestor of the Indian elephant of our day.
That Elephas planifrons cannot be regarded as the immediate predecessor of the species Elephas meridionalis and Elephas antiquus is held to be clearly shown by the
