omen
protruding, the legs rather short and bowed, the walk a waddling motion,
somewhat like that of the gibbon. It had small, deep-set eyes, greatly
protruding mouth with gaping lips, huge ears, and in general a very
ape-like aspect. Our warrant for this description of man's ancestor must
be left for a later portion of our work. We shall only say here that it
is based on known fact, not on fancy.

VI

THE DEVELOPMENT OF INTELLIGENCE

The full adoption of the erect attitude gave the ancestor of man an
immense motor supremacy over the lower animals, for it completely
released his fore limbs from duty as organs of support and set them free
for new and superior purposes. In all the animal kingdom below man there
exists but a single form that emulates him in this possession of a
grasping organ which takes no part in walking or in other modes of
locomotion. This is the elephant, whose nose and upper lip have
developed into an enormous and highly flexible trunk, with delicate
grasping powers. The possession of this organ may have had much to do
with the intellectual acumen of the elephant. Yet it is far inferior in
its powers to the arm and hand of man; while the form, size, and food of
the elephant stand in the way of the progress which might have been made
by an animal possessed of such an organ in connection with a better
suited bodily structure.

For a period of many millions of years the world of vertebrate life
continued quadrupedal, or where a variation from this structure took
place the fore limbs remained to a large extent organs of locomotion.
Finally a true biped appeared. For a period of equal duration the mental
progress of animals was exceedingly slow. Then, with almost startling
suddenness, a highly intellectual animal appeared. Thus the coming of
man indicated, in two directions, an extraordinary deviation from the
ordinary course of animal development. Both physically and mentally
evolution seemed to take an enormous leap, instead of proceeding by its
usual minute steps, and in the advent of man we have a phenomenon
remarkable alike in the development of the body and the mind.

So far our attention has been directed to the evolution of the human
body, now we must consider that of the human mind. In seeking through
the animal kingdom for the probable ancestor of man in his bodily
aspect, we were drawn irresistibly to the ape tribe, as the only one
that made any near approach to him in structure. I