298 



THE ANATOMY OF YERTEBRATED ANIMALS. 



The animal is supported by these greatly-developed nails, 

 and hence is said to be ungullgrade. The long axis of its 

 phalanges are greatly inclined to the surface upon which it 

 stands, while those of the metacarpals and metatarsals are per- 

 pendicular and greatly elongated. The wrist of the Horse 

 thus comes to occupy the middle of the length of its fore-leg, 

 and constitutes what is improperly called the " knee." The 



Fig. y7 --Longitudinal median section of the foot of a Horse. — 13, 14, 18. The three pba- 

 Lin^a. 16. The navicular sesamoid. 5. The flexor perforatus. 6. The flexor perforans. 

 19. Th^ hoof. 



heel is similarly raised to the middle of the hind-leg, and is 

 termed the " hock." The forearm and the leg are free, but 

 their motions are almost restricted to an antero-posterior 

 plane. The forearm is fixed in the prone position. The arm 

 and thigh are closely applied to the sides of the body and en- 

 closed in the common integument, so as to be capable of very 

 little proper motion. At the same time, the axis of the hu- 

 merus is inclined obliquely backward and downward, at right 

 angles with the long axis of the scapula ; and that of the 

 femur obliquely forward and doAvnward at right angles with 

 that of the os imiominatum * and the long axes of both these 



