It is generally supposed that the nails are the terminations of the sinews. All animals which have fingers have nails as well. In the ape they are long and overlapping,[338] like a tile, while in man they are broad: they will grow even after death. In the beasts of prey they are hooked, while in others, such as the dog, for instance, they are straight, with the exception, indeed, of the one which is attached to the leg in most of them. All the animals which have feet [and not hoofs], have toes as well, except the elephant; he, also, would appear to have toes, five in number, but rudely developed, undivided, and hardly distinct from one another, bearing a nearer resemblance, in fact, to hoofs than to claws. In the elephant the fore-feet are the largest, and in the hind-feet there are short joints. This animal is able, also, to bend the hams inward like a man, while in all the others the joints of the hinder legs bend in a contrary direction to those of the fore ones. Those animals which are viviparous bend the fore-leg forward, while the joint of the hind-leg is directed backward. CHAP. 102.—THE KNEES AND THE HAMS. In man the knee and the elbow bend contrary ways; the same is the case, too, with the bear and the ape, and it is for this reason that they are not so swift of foot as other animals. Those quadrupeds which are oviparous, such as the crocodile and the lizard, bend the knee of the fore-leg backwards, and that of the hind-leg forwards; their thighs are placed on them obliquely, in a similar manner to a man’s thumb; which is the case also with the multipede insects, the hind-legs only excepted of such as leap. Birds, like quadrupeds, have the joints of the wings bending forwards, but those of the legs backwards. CHAP. 103.—PARTS OF THE HUMAN BODY TO WHICH CERTAIN RELIGIOUS IDEAS ARE ATTACHED.