88 THE ARTISTIC ANATOMY OF ANIMALS 



the metatarsus, and the toes. These three portions are the 

 homologues of the carpus, the metacarpus, and the fingers, 

 which, as we have already seen in the case of the hand, are 

 the osseous groups which form its skeleton. The tarsus 

 is formed of short bones, as the carpus is ; these are, in 

 man, seven in number. The bones are arranged in two 

 rows : one, the posterior, formed of two bones superimposed — 

 the astragalus, by which the tarsus articulates with the leg, 

 and the calcaneum, which forms the prominence of the heel ; 

 and an anterior row formed of five juxtaposed ones — the 

 cuboid, situated externally, and the scaphoid internally, in 

 front of which are found the three cuneiforms. To the 

 tarsus succeeds the metatarsus, whose form reminds us very 

 much of that of the metacarpals. 



With regard to the toes, which we enumerate in proceeding 

 from the most internal to the most external, they are formed 

 of phalanges, which are three in number for the four outer 

 toes ; but the number is reduced to two in the case of the 

 first — that is, the so-called great-toe. 



The bones of the tarsus are not seven in all animals ; they 

 are fewer in ruminants and solipeds. We already know 

 that, in the latter, the metacarpals and the digits are 

 equally reduced in number ; the same is the case for the 

 metatarsals and the toes. We will analyze these differences 

 w^hen dealing with the species individually. 



When we studied the anterior limbs, we saw in passing 

 from the plantigrades to the digitigrades, and finally the 

 uugulates, or unguligrades, as the hand became hyperex- 

 tended, the carpus was raised and more and- more re- 

 moved from the ground. We shall estabhsh the existence 

 of the same condition in the posterior limbs ; in the 

 plantigrades the tarsus rests on the ground ; in the digiti- 

 grades it is removed from it ; while in the unguligrades the 

 distance which separates it from the point of support is 

 still more considerable ; and it is, indeed, necessary to 

 imagine that if these latter were plantigrades, would 

 occupy the position on the ground which is indicated by 

 Fig. 47. 



In veterinary anatomy the tarsus is called the ham ; a 



