social life. Fire-places, workshops, caves,
etc., enter the story in a later phase. Some authorities on prehistoric
man hold very strongly that during the greater part of the Old Stone
Age (two-thirds, at least, of the human period) man wandered only in the
company of his mate and children. [*]

* The point will be more fully discussed later. This account
of prehistoric life is well seen in Mortillet's
Prehistorique (1900). The lowest races also have no tribal
life, and Professor Westermarck is of opinion that early man
was not social.

We seem to have the most plausible explanation of the divergence of man
from his anthropoid cousins in the fact that he left the trees of his
and their ancestors. This theory has the advantage of being a fact--for
the Ape-Man race of Java has already left the trees--and providing a
strong ground for brain-advance. A dozen reasons might be imagined for
his quitting the trees--migration, for instance, to a region in
which food was more abundant, and carnivores less formidable, on the
ground-level--but we will be content with the fact that he did. Such a
change would lead to a more consistent adoption of the upright attitude,
which is partly found in the anthropoid apes, especially the gibbons.
The fore limb would be no longer a support of the body; the hand would
be used more for grasping; and the hand-centre in the brain would be
proportionately stimulated. The adoption of the erect attitude would
further lead to a special development of the muscles of the head and
face, the centre for which is in the same important region in the
cortex. There would also be a direct stimulation of the brain, as,
having neither weapons nor speed, the animal would rely all the more on
sight and mind. If we further suppose that this primitive being extended
the range of his hunting, from insects and small or dead birds to small
land-animals, the stimulation would be all the greater. In a word, the
very fact of a change from the trees to the ground suggests a line of
brain-development which may plausibly be conceived, in the course of a
million years, to evolve an Ape-Man out of a man-like ape. And we are
not introducing any imaginary factor in this view of human origins.

The problem of the evolution of man is often approached in a frame of
mind not far removed from that of the educated, but inexpert, European
who stands before the lowly figure of the chimpanzee, and wonders by