CHAPTER XXIX 



SOME IMPORTANT FACTS CONCERNING THE HORSE 



Base of support. — The horse's legs are his base of support, just as 

 the table legs support the table. The longer the legs, the less stable 

 the base of support. The smaller the base of support, the less stable 

 it will be. The less stable the base of support, the greater the speed 

 of the horse; while the greater the stability, the greater the power for 

 draft. Any object will be most stable when the center of its weight 

 is directly over the center of its base of support. In horses the center 



i/ertebrdl sp'me 



long postern 

 short poitern 



Fig. 155. — Attachment of fore leg to body. Cross-section through chest show- 

 ing the bones of the fore leg and the muscular attachment of leg to body. 



of weight is far forward, lying immediately behind the shoulders. 

 Thus the fore legs support much more of the weight of the horse than 

 do the hind legs, in fact it is the function of the forequarters to support, 

 and of the hindquarters to propel. This is the more clearly shown 

 when we examine the anatomy of the horse, for we find that the hind 

 legs are attached to the trunk by the strong ball-and-socket joint, 

 while the fore legs are not directly attached to the trunk but are con- 

 nected by intervening muscles which form a sort of sling which sus- 

 pends the body between the two fore legs. The muscle attaching the 

 fore limb to the trunk is the serratus magnus, an enormous triangular 

 muscle which originates on the upper part of the internal surface of 



413 



