sly swinging the arms
might seem quite as awkward to a gibbon as its grotesque posture does to
us.

The orang-outang comes next in this series. It inhabits the islands of
Borneo and Sumatra, where we find two distinct species. It is a reddish
colored animal standing about four feet four inches high, with rather long
hair. It is bulky, slow and deliberate in action, and when it walks in a
semi-erect position it rests its knuckles upon the ground, swinging its
long arms as crutch-like supports. Like the gibbon, it does not walk upon
all four feet in the way that the monkeys and baboons do, and we find in
the still further development of the brain and the higher arch of the
cranium the reasons for its semi-erectness. It cannot remain with its
hands and feet upon the ground and bend back its head so as to direct its
vision forward.

The chimpanzee of intertropical Africa brings us to a still less
monkey-like and more manlike stage. This creature attains the height of
five feet, which is more than that of some of the lower races of man. It
possesses large ears and heavy overarching brows; its thumb and great toe
are more like those of man, though its foot is still practically a hand.
Its lower limb curves like those of the other apes, and its soles are
turned toward one another; in brief, it is naturally bow-legged, a
character that adapts it for a tree-climbing life. This animal also is
nearly, though not quite, erect. It shows a most marked advance in the
matter of the brain, for the cerebrum is richly folded or convoluted, and
with this higher degree of physical complexity is correlated its superior
intelligence; it is well known that chimpanzees can be taught to wear
clothing and to use a cup and spoon and bowl like a human child. Indeed,
in mental respects, the chimpanzee surpasses all of the other mammalia,
with the sole exception of man. An eminent psychologist has stated that it
is about the equal, in mental ability, of a nine months' old human infant.

The last form among the apes, the gorilla, is one that brings us to a
realization of our own human physical degeneracy. The animal lives in West
Equatorial Africa, and it is a veritable giant in bulk, though its height
may not exceed five feet six inches. The heavy ridges over the eyes, the
upturned nostrils and triangular nose, place it near to the orang-outang,
but it is superior to that form in its relatively greater brain-box, and
in the fact that its heavy lowe