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.