The belly is very large, and it is kept from pushing into the chest by the capacity given to the space within the ribs and breast-bone, by a bulged-out state of the ribs at the back, and the projection of the breast-bone. Hence, the frog-like figure looks asthmatical; and as it is very high-shouldered, there is but little neck.
All this bulging has not only reference to the maintenance of the capacity of the lungs, and its independence of the great stomach, which, when full, would tend to press in all directions, but it enables the muscles of the back and shoulders, which have so much to do with climbing, to be large and vigorous. More space is afforded for the insertion or attachment of muscular fibres.
The blade-bone does not add to the bulk of the shoulders, for it is rather long and narrow for a great Ape; and its spine, which has so much to do with the muscles which lift up the arm, is very much aslant, and in the best direction for constant climbing, instead of much walking on the knuckles. And that climbing and holding on are the usual motions may be credited, it is only necessary to notice that the arms and the fingers are long, and that the tips of them touch below the knee when the skeleton is placed upright. Moreover, this great length is accompanied by corresponding strength, and also by a very curious condition of the hands.
The Koolo has a larger hand in relation to its breadth than the Gorilla, and there are no bunches of muscle forming rounded swellings or balls under the thumb and little finger. On the contrary, the long and narrow palm is, as it were, bent across, as if it could fit capitally on to a bough. There is no doubt that this Ape, like all the others, does a good deal of swinging, by holding on to boughs with its hands, when the arms are straight above the head; and that they move along a bough, or from tree to tree, in this position, without bending the elbow, and with considerable speed. This method of getting along may also be seen in Chimpanzees. Evidently the curved palm will be of immense advantage in such actions, and especially when it is combined, as it is in the Koolo-Kamba, with a slightly bent-downwards condition of the fingers. The bones (phalanges) of the fingers are long, and each is slightly curved, and not straight, as in man and the great Apes already noticed, so that their three bones, when in their proper position, are decidedly out of a straight line, and present a general curve, which is rendered all the more decided by the bend in the palm. All this is very useful for grasping and holding on. But it is not all; in man and the other great Apes, the wrist consists of two rows of small bones, one placed before the other: the first row is jointed to the bones of the fore-arm, at what is called the wrist-joint, which moves forwards and backwards as a hinge; and the second row is so jointed on the first row that there is no movement, and in front it is jointed to the bones of the palm, and to those of the thumb. Now in the Koolo the second row of wrist-bones—or as they are called from the Latin, carpus, a wrist—carpal bones are movable on the first row, and muscular exertion can bend, not only the metacarpal bones and the fingers, but also the wrist-bones. Hence the hand is more movable in the bending direction than that of man, and the reason is because of the peculiar requirements of the creature’s life. The thumb is small, and only reaches the first joint of the forefinger: its tip can only touch the tip of one finger at a time, and not those of all, as in man, and therefore it is not of much use in distinguishing objects by touch; moreover, it cannot be stuck out far—and this is necessary, for in climbing its tip is required to be as close to the fingers as is possible. The muscles of the hands and arms resemble those of the Chimpanzee generally, and will be noticed in describing it.
When the Koolo-Kamba walks, it does so like the Gorilla, by leaning on the backs of its fingers, and hence it has callous pads on the back of their second bones. All the peculiar construction of the hands and wrist bears a relation to the vast muscular development of the muscles of the back of the chest and shoulders in the process of climbing; and it is to be observed, as it was in the instance of the Gorilla, that these muscles have more to do with such actions than those of the chest, which go to the arm, and which are so much used in man for that purpose. The muscles of the chest are not large and strong in the Apes, for, as has already been mentioned, they climb with the back of the hand towards the face, and do not attempt, like man, to lift the body with the palm and nails turned towards him. This last proceeding necessitates large chest muscles, and the former large ones at the back of the shoulders.
There is something remarkable about the haunch-bones, or those parts of them which support the body when sitting. In man they are well in front of the end of the back-bone, which tapers off and turns in a little, and forms a rudiment of a tail. These tuberosities of the haunch-bone (as they are called, because they are swollen out and flattened for the especial purpose in man) are placed, in the Koolo-Kamba, behind the end of the spine or the true rudiment of the tail, and this throws all the under parts backwards, giving the animal a thorough Baboon and animal character. Oddly enough, the rudiment of the tail in this Ape is smaller than in man.
A study of the foot shows that it is of immense use in holding on and in climbing, and of none in walking. It looks more like a small hand, furnished with a great thumb, than a foot with a toe-thumb.
It differs from human feet in the length of the toes, and this is rather an interesting artistic point, for there is some diversity in the opinions regarding which should be the longest toes in man.
The Greek statues—those grand models of the highest types of mankind—very constantly have the second toe the longest, and reaching more to the front, when the foot is on the ground, than the great toe and the third. Nowadays, after men have had their feet pinched, cabined, and confined in all sorts of boots and shoes, generation after generation it is wonderful that their toes should be of any shape at all; and, therefore, it must be anticipated that the Grecian type will not always prevail. Nevertheless, although the great toe is often the longest, the third toe never is, except there is some decided deformity, like double toes. It is, however, the third toe which is the longest in the Ape, just as the third finger of the hand is the longest in man; and hence the Ape’s foot, with its great thumb, is in this hand-like. But as has been mentioned before, bone for bone, and almost muscle for muscle, the human and Ape’s foot agree, and the hinder extremity of this last is really a foot with a toe-thumb.
On looking at the head of the Koolo, one is struck with the great ears, which are larger than those of the Apes already described, and almost as large as, but less detached, than those of the Chimpanzee. The skull is globular, and with a low contracted forehead receding behind the brow crests; but there are only faint ridges on its sides, although the muscles of the jaw are large, and they come from the sides of the skull. The head is very hairy, and the face, which is very prognathous (Greek, gnathos, jaw or mouth), or projecting in front, is black. It is rendered very tigerish and ugly by the flat nose merging into a wide, thick, projecting upper lip, without any furrow; and the mouth looks like a wide slit, there being no chin, on account of the pouting nature of the great lips.