EXTERNAL TARTS OF THE FOOT. 251 



rapid return assists in raising the limb. This action is thus 

 clearly described by Mr. Percivall : — " Furthermore, it seems 

 to us that these elastic parts assist in the elevations of the 

 feet from the ground in those places in which they are 

 called into sudden and forcible action. The suspensory 

 ligament, by its reaction instantaneously after extension, 

 aids the flexor muscles in bending the pastern-joints. The 

 astonishing activity and expedition displayed in the move- 

 ments of the race-horse at speed, seem to be referable, in 

 part, to the promptitude with which the suspensory ligament 

 can act before the flexor muscles are duly prepared ; the 

 latter, we should say, catch, as it were, and then direct the 

 limb first snatched from the ground by the powers of 

 elasticity." 



The spring and elasticity in the action of a horse de- 

 pends, in a great measure, upon the length and obliquity of 

 the pasterns. It should be long in the race-horse, less so in 

 the hunter, still shorter in the hackney, and considerably 

 less so in the cart and dray-horse. In the latter the con- 

 cussion is exceedingly little, because their movements are 

 slow; and the short and upright pasterns enable him to 

 sustain and drag the heavy loads which he is destined to 

 support and move forward. But in a horse that is to be 

 used for the saddle, the short and upright pastern is not 

 only a great defect, but is also very unsafe, as he is exceed- 

 ingly liable to come down when trotting. Besides, such 

 joints soon begin to knuckle over, even with ordinary work, 

 which is the precursor of ossification of the cartilages, ring- 

 bone, and contracted feet. 



EXTERNAL PARTS OF THE FOOT. 



THE CRUST OR WALL OF THE HOOF. 



The formation of the foot of the horse fits him, as well 



