164 
COMPARATIVE ZOOLOGY. 
Fig. 128.—Feet of Carnivores : A, Plantigrade {Bear); B, Pinuigrade {Seal): C, 
Digitigrade {Lion). 
some may be wanting, so that we have one-toed animals 
(as Horse), two-toed (as Ox), three-toed (as Rhinoceros), 
four-toed (as Hippopotamus), and five-toed (as the Ele¬ 
phant). The Horse steps on what corresponds to the nail 
of the middle finger; and its swiftness is conditioned on 
the solidity of the extremities of the limbs. Horses of 
the greatest speed have the shoulder-joints directed at a 
considerable angle with the arm. 
Fig. 12£*. Feet of Hoofed Mammals: A, Elephant; B, Hippopotamus; C, Tthinoc- 
eros; I), Ox; E, Horse, a, astragalus; cl, calcaneum, or heel; s, naviculare; b, 
cuboides; ce, ci, cm, cuneiform bones; the numbers indicate the digits in use. 
