84 FORM AND ACTION. 



still it is surprisingly short; at the same time, it is certainly the 

 strongest bone in the body, on account of this shortness being 

 combined with extraordinary development of its shaft and ex- 

 tremities. Had Sampson armed himself with the femoral-bone 

 instead of with the jaw of an ass, he would have found his weapon 

 for combatting the Philistines a greatly more efficient one. 



Any disproportionate length of this bone in the horse would have 

 thrown the stifle too low down, out of its natural and proper situation, 

 which is on a level with the inferior line of the body and with the 

 elbow, the joint in the fore extremity to which the stifle corresponds: 

 the only augmentation in length the bone admits of being that 

 which it derives from straightness in the quarters, or the least 

 possible declination in the position of the pelvis. The straight and 

 lengthy quarter, therefore, it is which has — providing the depth 

 of the carcass be undiminished — the greatest length of femoral bone ; 

 the short and drooping quarter, the least. Here presents itself 

 another instance to shew that when stride or speed is required 

 length is given : a horse with long femoral bones will be enabled 

 in action to throw his hind feet farther forward than another with 

 short ones ; that motion in the hip-joint which will advance the 

 short bone as equal to three will project the long one as equal to 

 four. 



I said the hip-joint was of the ball and-socket character, and 

 therefore it possesses, to a greater or less extent, a rotatory mo- 

 tion. Through its means it is that the animal has the power of 

 " tucking his haunches in," or placing his hind foot centrically 

 underneath his body, in the position, of all others, the most effec- 

 tive for the propulsion of the machine in action : unless from the 

 breadth and position of the pelvis, and the connexion with it and 

 conformation of the hind limbs, he derive this power from the 

 hip joint, from no other joint, from want of the rotatory power, can 

 such action proceed. It is quite a mistake to suppose that such 

 " tucking in" can be produced by the hocks, they admitting but of 

 simple flexion and extension. Both the fore and hind extremities 

 derive what faculty of lateral and rotatory motion they possess — 

 the power of throwing the legs and turning the toes inward or 

 outward in action — from ball-and-socket joints: the fore extremity 

 from the shoulder joint, the hind extremity from the hip joint. 



