[41].
Rhinoceros.
[42].
Ox.
[43].
Horse.
I have said (page [10]) that the inner toe is incomplete in all animals, forasmuch as, in none, does it possess the same complement of bones as do the other toes. You will not be surprised to find, therefore, that it is the first to be missing. The Elephant goes upon five toes; but if you look closely you will perceive that the inner toe (fig. 39, I.) has not attained even its usual incomplete number of bones. It is short of one; and the inner wedge-bone, which looks like a metacarpal bone, is prolonged, downwards, to supply the place, and to give sufficient length to the toe. The same thing may be seen in some other animals, and it is interesting as shewing the first indication of departure from what may be called the standard number of the phalanges. In the Hippopotamus (fig. 40) we have an additional stage of imperfection in this same toe; for here there is only one small bone to remind us of the existence of the toe (it is the same in the Rhinoceros, I.); all the rest have failed to be developed; and the animal, consequently, goes upon four toes. Next the failure appears on the outer side of the foot, and affects the little toe. Thus, the Rhinoceros (fig. 41) goes upon three toes—namely, Nos. II. III. and IV.—and there is scarcely a trace either of the first toe or of the fifth. In Ruminating animals, as the Ox (fig. 42), the second toe is wanting, as well as the first and the fifth; so that the foot rests upon two toes (Nos. III. and IV.); and in the Horse (fig. 43), as we have already seen, only one toe—the middle one (No. III.)—is developed sufficiently to reach the ground.
Fig. [44]. Gorilla.
Whatever pretensions to Humanity the Monkey may make—and they are sufficiently striking to render some persons very uncomfortable on the score of relationship—he is certainly far removed from us in the construction of the foot (fig. 44); and the good people to whom I have alluded may derive consolation from the reflection that, in this respect at least, there is very little indication of cousinship. Indeed we ought not to speak of his foot at all; for the part which corresponds with the human foot does not even deserve that name. It is so much more like a hand, that the term four-handed, or quadrumanous, is by naturalists applied to this class of animals. There is scarcely any plantar arch; the animal bears, chiefly, upon the outer edge of the foot; the digits are long and strong; and the inner one, instead of being parallel with the others, diverges from them so as to constitute a true thumb instead of a great toe. All these points are very suitable for enabling the animal to cling to branches of trees, and for other prehensile purposes; but they unfit him for the upright posture, and render it impossible for him to walk steadily upon his lower limbs.
