266 



THE EXTERIOR OF THE HORSE. 



The hock with a small angle, which we will call common, because 

 it is ordinarily met in horses for light-draught and rapid heavy- 

 draught services, is, in our opinion, more favorable to the production 

 of force. Does this mean that the straight hock is defective for all 

 laborious services, and that it is only observed in long-striding horses ? 

 By no means. It is rather frequently seen in our heavy, lymphatic 

 horses, which our measurements have proved ; it should not, in such 

 cases, be considered as defective unless it at the same time lacks width, 

 which is not rare, or unless its deficiency is not compensated by a mus- 

 cular and powerful leg. 



b. The Canon, Oblique forward and downward. This 

 conformation, in which the canon is deviated in advance of the verti- 

 cal line falling from the point of the buttock, has 

 caused the hock to be qualified elbowed or angular 

 (Fig. 80). 



This hock, says H. Bouley, 1 "always appears 

 wide in its superior part, because its angularness 

 results in a separation of the calcaneus from the 

 tibia and, consequently, places the calcanean cord 

 at a greater distance from the latter bone ; whence 

 a widening of the external surface. This bending 

 of the region, besides, also has the effect of placing 

 the arm of the calcanean lever in the most favor- 

 able condition for the production of force. 



"But, by the side of these advantages, real 

 disadvantages present themselves, which give 

 ample reasons for considering this conformation 

 as being defective. First, the column of sup- 

 port below the tibia being situated obliquely, it results that the press- 

 ure of the weight of the body, instead of being transmitted to the 

 ground by the bones exclusively, as in the vertical position of this 

 segment, causes a strain, proportionate to the degree of the obliquity, 

 on the ligaments which unite the tarsus with the metatarsus as a 

 whole, and imposes upon them an abnormal function. In addition, 

 these ligaments, during locomotion, are subjected to all the greater 

 strain, because the muscular force finds, in the direction of the cal- 

 canean lever-arm, more favorable conditions for its development. 

 These are two causes which fatigue the apparatus of the hock more 

 and hasten its premature ruin. Experience bears witness to this 



FIG. 80. 



1 H. Bouley, loc. cit., t. x. p. 579. 



