76 CONFORMATION AND ITS DEFECTS 



be transferred to the canon, thus enabling the former to rest and re- 

 cuperate after exertion and fatigue. The posterior part of this region is 

 formed by two tendons, the flexor pedis perforans and the flexor pedis 

 perforatus. These two long, dense cords, after traversing the posterior 

 part of the canon, are continued downward over the fetlock-joint, to which 

 they give support, and finally become attached to the pedal or foot bone 

 and the short pastern respectively. 



The length of this region is greater behind than in front in all varieties 

 of the horse, and, as might be expected, all things being equal, it is also 

 slightly longer in the race-horse, the hunter, and other fast-moving types 

 than in the heavy, slow-moving draught-horse. 



Considered in relation to the arm in front and the second thigh or 

 leg bone behind, the canon in the thoroughbred should be short, for as 

 Goubaux and Barrier observe: "When it is thus the muscles experience 

 less fatigue and contract to better advantage. A short canon is less 

 heavy, oscillates more freely . . . and does not necessitate the same 

 elevation of the limb above the ground to reach the limits of its move- 

 ments." 



Viewed in profile the canon should be straight and form a line per- 

 pendicular to the ground. Any marked deviation in this respect is pre- 

 judicial to the integrity and consequently to the work-bearing capacity of 

 the legs. It tends to bring about an unequal distribution of weight on the 

 underlying joints, and to impose undue strain on some of the connecting 

 ligaments, which, sooner or later, results in active disease. 



As the region of the canon is made up of weight-bearing structures, 

 size and strength in its several parts are of the first importance to the 

 resistance of wear and tear and prolonged endurance. 



In every variety of the horse this part should present great width 

 from front to back, with little or no variation from beneath the knee 

 downward (fig. 57, and Plate IX, fig. 1) until approaching the fetlock- 

 joint, where it will gradually widen out in conformity with a relatively 

 large articulation. 



This quality of amplitude is not only an evidence of power in itself, but 

 also of a high state of development of those parts related to it' — the knee- 

 joint above, the fetlock below, the muscles of flexion and extension, and 

 the tendons which proceed from them and concur in the formation of the 

 canon. 



Most horsemen know how important it is, and insist on substantial 

 measurement below the knee. This is no doubt a good working rule, but 

 it must be oliserved that lightness of the parts under consideration is 

 not always to be regarded as an absolute defect of conformation, but 



