“It is not as powerful an animal as the Gorilla, its chest is not so large, but the arms and fingers are a little longer, and this is the case with the toes also. The nose is not so prominent, but the mouth is wider and the ears are larger. Its chin is rounder, and has more small hairs, and the side of the face is thinly covered with hair, commencing about the middle of the ear, and these would seem to be signs of an incipient beard and whiskers. The lower parts of the body are bare, and the skin is white there.”
Apparently the disposition and temper of the Nschiego are better than those of the Gorilla; it is less ferocious, and is even docile in captivity. It has not the hideous expression of the great Ape, for there is something of a forehead above the ridge of the eyebrow, and there are no great crests on the head, which is rounder than that of the Gorilla. The teeth are rather smaller, but are of the same number. The height is less than that of the female Gorilla, as a rule; and the male of this bald kind is larger than its female; whilst the little young ones differ in their colour from both, being white. Finally, it would appear that there are hard callous pads on the back of the fingers, that the hand is larger than the feet, and that the tips of the fingers reach a little below the knee. Associated with the Gorilla and with the Chimpanzee in the forests of Equatorial Western Africa, the Bald-headed Troglodyte appears to have a restricted geographical range, and not to be found over so large a district as its companions, for it was only met with on the table-lands of the interior, and in the densest forests.
Subsequently Du Chaillu had a good opportunity of substantiating his statements about the nests.
“On our way down, at sunset of the third day, we heard the call of a Nschiego Mbouvé (Troglodytes calvus). I immediately caused my men to lie down, and was just getting into a hiding-place myself, when I saw, in the branches of a tree at a little distance, the curious nest or bower of this Ape; hard by, on another tree, was another shelter. We crept up within shot of this nest, and then waited, for I was determined to see once more the precise manner in which this animal goes to rest. We lay flat on the ground, and covered ourselves with leaves and bush, scarcely daring to breathe, lest the approaching animal should hear us. From time to time I heard the calls. There were evidently two, probably male and female. Just as the sun was setting, I saw an animal approach the tree. It ascended by a hand-over-hand movement, with great rapidity, crept carefully under the shelter, seated itself on the crotch made by a projecting bough, its feet and haunches resting on this bough; then it put one arm about the trunk of the tree for security.
SKELETON OF NSCHIEGO.
“Thus, I suppose, they rest all night; and this posture accounts for some singular abrasions of hair on the side of the Nschiego Mbouvé. At a little distance off I saw another shelter made for the mate. No sooner was it seated than it began again to utter its call. It was answered; and I began to have the hope that I should shoot both animals, when an unlucky motion of one of my men roused the suspicions of the Ape in the tree. It began to prepare for descent, and, unwilling to risk the loss of this one, I fired. It fell to the ground dead. It proved to be a male, with the face and hands entirely black. As we were not in haste, I made my men cut down the trees which contained the nests of these Apes. I found them made precisely as I have before described, and as I have always found them, of long branches and leaves, laid one over the other very carefully and thickly, so as to render the structure capable of shedding off water. The branches were fastened to the tree in the middle of the structure by means of wild vines and creepers, which are so abundant in these forests. The projecting limb on which the Ape perched was about four feet long. There remains no doubt in my mind that these nests are made by the animal to protect it from the nightly rains. When the leaves begin to dry to that degree that the structure no longer throws off water, the owner builds a new shelter, and this happens generally once in ten or fifteen days. At this rate the Nschiego Mbouvé is an animal of no little industry.”
The differences between the outside appearance and the intelligence and temper of this Bald-headed Ape and those of the Gorilla are accompanied by certain internal ones. A careful examination of the skull of the Tschiégo, as its clever French describer, Duvernay, calls it, shows that it has smaller ridges, a less prominent muzzle, and a wider and shorter roof of the mouth than the Gorilla. The last of the upper crushing, or back teeth, is the smallest. In the Gorilla they are nearly equal in size. The lower jaw in the Nschiego has three nearly equal-sized molar or back teeth, and the first and the second have five projections or cusps, but the last has only four. In the Gorilla it has five cusps. These minute differences are probably constant, and therefore must not be passed over, although they may seem to be of no importance to the creatures. But the classification of animals can only depend upon the presence or absence of structural peculiarities; and when such and such a structure exists in one, and not in another, they cannot both be of the same kind. According to the relation of the structure to the life, and according to its being constantly found, so is it important in deciding whether the “kind” is a species, or a mere variety or race.