Gorillas & Chimpanzees

by R. L. Garner

Nos. 2, 3, 4 and 5 are female; the others are all male.

Nos. 3, 4, 5, 7, 9 and 10 belong to the Liverpool Museum, but are shown here for comparison. The other four are all at Toronto University.

While this series is not complete in either sex, it is an excellent one for comparative study.

I do not know whether the heads of those with the crests were the same colour as No. 6 or not, but the ntyii, which I have mentioned as possibly a new species of the gorilla, does not have this crown of red. His ears are also said to be larger than those of the gorilla, but smaller than the chimpanzee's, and he is reputed to grow to a larger size than either of them.

The skin of the gorilla is a dull black or mummy colour over the body, but that of the face is a jet black, quite smooth and soft. It looks almost like velvet.

One fact peculiar to this ape is, that the palms of both hands and feet are perfectly black. In other animals these are usually lighter in colour than the exposed parts. In all races of men, in all other apes, monkeys, baboons, and lemurs, the palms are lighter than the backs of the hands, and the same is true of the feet. The thumb of the gorilla is more perfect than that of the chimpanzee, yet it is smaller in proportion to the hand than in man. The hand is very large, but has more the shape of the hand of a woman than that of man. The fingers taper in a graceful manner, but appear much shorter, by reason of the web alluded to, than they really are. It is not really a web, in the true sense, but the integument between the fingers is extended down almost to the second joint, but the forward edge of the web, when the fingers are spread, is concave; when brought together, the skin on the knuckles becomes wrinkled, and the web almost disappears. This effect is more readily noticed in the living animal than in the dead. The texture of the skin in the palms is coarsely granulated, and the palmar lines are indistinct. The great toe sets at an angle from the side of the foot, like a thumb, but has more prehensile power than that of the hand; but the foot is much less flexible, and has less prehensile power.

At this point I desire to draw attention to one important fact. The tendons of the foot, which open and close the digits, are imbedded in the palm in a deep layer of coarse, gristly matter, which forms a pad, as it were, under the sole of the foot, and prevents it from bending; therefore it is not possible for the gorilla to sleep on a perch. In this respect he resembles man more than the chimpanzee does, but it is quite certain that neither of them have the arboreal habit. The gorilla is an expert climber, but cannot sleep in a tree. In the hand the tendons which close the fingers are the same length as the line of the bones, and this permits him to open the fingers to a straight line, which the chimpanzee cannot do.

One other important point I desire to mention. The muscles in the leg of a gorilla will not permit it to stand or walk erect. The large muscle at the back of the leg is shorter than the line of the bones of the leg above and below the knee; and when this muscle is brought to a tension, those bones form an angle of about 130 degrees, or thereabouts; and so long as the sum of two sides of a triangle is greater than the other side, a gorilla can never bring his leg into a straight line. In the infant state the muscle is pliant or elastic, and the bones less rigid, so that in that state it can be made nearly straight. The habit of hanging by the arms and walking with them in a straight line develops the corresponding muscle in that member, so that the bones can be brought in line.

The gorilla can stand upon his feet alone, and walk a few steps in that position; but his motion is awkward, because his knees turn outward, forming an angle of 30 or 35 degrees on either side of the mesial plain. He never attempts to walk in this position, except at perfect leisure, and then usually holds on to something with his hands. The tallest gorilla known, when perfectly erect, is about 6 feet 2 inches.

The leg of the gorilla from the knee to the ankle is almost the same size. In the human leg there is what is called the "calf" of the leg, but this in the apes is very small; however, there is a slight tendency in that direction, and it must be noted that in the human species the calf of the leg appears to belong to the higher types of men; and as we descend from the highest races of mankind this character disappears as we approach the savage. The pigmies and the bushmen have the smallest of any other men. It is not to be inferred from this that apes would ever have this feature developed in them by elevating them to a higher plane so long as they remained apes; but it is possible that such a result would follow in the course of time.