e case of other
domesticated animals. In short, it seems by all odds to be the animal
best fitted mentally to serve as the basis of a high intellectual
development, as it is the best fitted physically to change from the
attitude of the quadruped to that of the biped.

The anthropoid apes in general manifest a reversion from the social
toward the solitary state, this condition reaching its ultimate in the
orang, which is one of the most solitary of animals. The smaller forms
are the most social, the gibbons being decidedly so. There is very good
reason to believe that the man-ape was highly social, if we may judge
from what we find in all races of men, and all grades, from the savage
to the civilized. This animal was thus in a position to avail itself of
all the advantages of the social habit, and to gain the mental
development thence arising. How long ago it was when it left the trees
and made its home upon the ground, it is impossible to say. It may have
been as far back as the early Pliocene or the late Miocene Period, or
even earlier. As yet its brain was probably no more developed than in
the case of the other anthropoids, perhaps less so than in the existing
species. But in its new habitat it was exposed to a series of novel
conditions that must have exerted a healthful and stimulating influence
upon its mind.

If it had remained in the trees we should probably to-day have only a
man-ape still. Leaving their safe shelter for the ground, it became
exposed to new dangers and was forced to fit itself to fresh conditions.
Prowling carnivorous animals haunted its new place of residence, and
these it had to avoid by speed or alertness of motion, or combat them by
strength and the use of weapons. The carnivorous tastes which it had in
all probability gained, made it a creature of the chase, pursuing swift
animals, capturing them by fleetness or stratagem, or bringing them down
with the aid of clubs and missiles. Such a new series of duties and
dangers could not fail to exert a vigorous influence upon a brain
already quick of thought and susceptible to fresh impressions, and we
may well conceive that the man-ape then entered upon a new and rapid
phase of mental progress, its brain developing in powers and growing in
dimensions as it slowly became adapted to its new situation and grew
able to cope with fresh demands and critical exigencies.

There is still another influence which has had its share, perhaps a very
promine