Ixxiv INTRODUCTION. 



serted the humerus or bone of the shoulder. The humerus 

 corresponds with the bone of the same name in man, that is, 

 with the portion of the human arm which is between the 

 elbow and shoulder, but is so covered with muscles in the 

 horse, as to seem to form a part of the trunk. It is bent 

 downwards and backwards in a direction opposite to that of 

 the shoulder-blade, by which disposition the parts act like a 

 spring to lessen the effects of those terrible shocks which 

 they sustain, when, the animal being raised from the ground, 

 his weight is received upon his fore extremities. The head 

 of the humerus working in a very shallow cavity in the shoul- 

 der-blade, the bone has great freedom of motion. Its lower 

 extremity is fitted by a hinge-like joint into the next in 

 order of the bones of the limb, namely, the bone of the fore- 

 arm. 



The bone of the fore-arm corresponds with that portion of 

 the human arm which is between the elbow and the wrist, 

 but the fore-arm, in the human subject, consists of two bones, 

 termed respectively radius and ulna. In the horse, there 

 were likewise two bones in the young state, but they became 

 joined together ; though the ulnar portion, as in the figure, 

 is still to be distinguished projecting behind the upper part 

 of the fore-arm, and receiving the name elbow in the horse 

 as in man. To the elbow are attached powerful muscles, 

 for extending the limb ; and its size is one of the points 

 looked to by jockeys, as indicative of what is termed action. 



The part termed the knee in the horse corresponds with 

 the wrist of the human arm, and is for this reason termed 

 carpus. It is composed of seven, and sometimes of eight, 

 small bones. These bones serve for the attachment of 

 muscles, and for giving flexibility to the joint. By being 

 many, the weight is divided amongst them, and thus the ha- 

 zard of fracture or dislocation is lessened. They are sepa- 

 rated by elastic cartilage, bound firmly together by ligaments, 

 and kept constantly lubricated by a secreted liquid. They 

 form an exceedingly strong and perfect joint, scarcely subject 



