166 SKELETON OF THE RHINOCEROS. 



whicli they are therein inserted becomes more favorable 

 for tlieir force ; the longer, therefore, and the more hori- 

 zontal the pelvis, the better the hind -quarter of the horse, 

 and its qualities for swiftness and maintenance of speed 

 depend much on the "good point" due to the development 

 of this part of the skeleton. The femur, 65, is character- 

 ized by a third trochanter springing from the outer part 

 of the shaft before the great trochanter. There is a splint- 

 shaped rudiment of the proximal end of the fibula, 67, 

 but not any rudiment of the distal end. The tibia, 66^ is 

 the chief bone of the leg. The heel-bone, "calcaneum," 

 is much produced, and forms what is called the "hock." 

 The astragalus is characterized by the depth and obliquity 

 of the superior trochlea, and by the extensive and undi- 

 vided anterior surface, which is almost entirely appro- 

 priated by the naviculare. The external cuneiforme is 

 the largest of the second series of tarsals, being in pro- 

 portion to the metatarsal of the large middle digit, m, 

 which it mainly supports. The diminished cuboides arti- 

 culates partly with this, partly with the rudiment of the 

 metatarsal corresponding with that of the fourth toe, iv. 

 A similar rudiment of the metatarsal of the toe, corre- 

 sponding with that of the second, ?V, articulates with a 

 cuneiforme medium — here, however, the innermost of the 

 second series of tarsal bones. 



Of all the other known existing hoofed quadrupeds, it 

 would hardly be anticipated that the rhinoceros presented 

 the nearest afiinity to the horse ; one might rather look to 

 the light camel or dromedary; but a different modification 

 of the entire skeleton may be traced in the animals with 

 toes in even number, as compared with the horse and other 

 odd- toed hoofed quadrupeds. In an extinct kind of horse 

 {IIippopotJiermm)j the two splint-bones are more developed, 



