POSTERIOR MEMBER. 



269 



order that the tarsal apparatus may fulfil its functions well, it is not 

 enough that it should be in a plane parallel to the axis of the body, 

 but it is also necessary that the median line of the member divide it 

 into two very equal moieties. If this condition be not realized, the 



Fig. 81. 



Fig. 82. 



region of the hock is displaced inwardly or outwardly, and becomes 

 the seat of irregularities in its contact more or less prejudicial to the 

 integrity of the locomotory machine. 



When the hocks are strongly convex on their internal face from 

 above to below, they are most ordinarily angular in front, and the 

 animal is close behind. 



The deviation opposite to the latter, and common in horses too 

 open behind, consists in a rather strongly-marked concavity of the 

 whole of the internal surface of the member, in virtue of which the 

 calcanei become very diverging, while the two hoofs, nearer each other 

 than they should be, converge and even touch each other in the region 

 of the toes. A horse offering this conformation could be called boio- 

 legged, on account of its analogy to the aspect of the man whose legs 

 are thus directed. In both forms the hock does not give the natural 

 impulsion to the body, and the members move in a very ungraceful 

 manner. (See Axes of 3Iembers.) 



Diseases and Blemishes. — The alterations of which the hock 

 may be the seat, says H. Bouley,^ are numerous, varied, and often of 

 extreme gravity. They may affect any of the constituent parts of 



1 H. Bouley, loc. cit., p. 586. 



