156 



THE STKUCTUEE OF THE HOESE 



the c hip-joint.' There is no essential anatomical differ- 

 ence in the construction of the ' pelvis,' as the whole 

 girdle is called, in man and in the horse, each lateral 

 half being in both originally composed of three distinct 

 bones — the ilium, the ischium, and the pubis — which 

 unite before the animal is full grown to form a solid mass, 

 which has received from the old anatomists the curious 

 name of os innominatum. The actual form of the bones 

 presents considerable differences, the comparatively 

 broad and basin-like pelvis of man relating chiefly to 

 the adaptation of the body to the upright position. 



The bone of the first segment of the limb proper is 

 called the femur or thigh-bone. As in the correspond- 

 ing bone of the fore limb, it is in the horse compara- 

 tively stout and short, and placed very obliquely, the 

 lower end advancing by the side of the body, and being 

 so little detached from it that the knee-joint appears to 

 belong as much to the trunk as to the limb ; a position 

 altogether in contrast to that of the knee of man, sepa- 

 rated from the body by the whole length of the elon- 

 gated, free, vertically placed thigh (see Frontispiece). 

 The bone itself has, in addition to the usual two rough 

 processes near the upper end for the attachment of 

 muscles (the trochanters) found in man and other mam- 

 mals, a prominent compressed ridge, curving forwards, 

 placed on the outer edge of the shaft of the bone, some- 

 what lower down than the other two. This, the so- 



