104 Management and Treatment of the Horse. 



navicular bone, as well as by the tendon and the 

 pastern, and being incapable of condensing itself 

 into less compass is forced out on each side of 

 them and expands the lateral cartilages. These 

 again by their inherent elasticity revert to their 

 former situation when they are no longer pressed 

 outward by the frog. It thus appears that by a 

 different mechanism, but both equally admirable 

 and referable to the same principle of elasticity, 

 the expansion of the upper and lower parts of the 

 hoof are affected ; the one by the descent of the 

 sole and the other by the compression and rising 

 of the frog. The preservation and usefulness of 

 the limbs of the horse are chiefly maintained by 

 this upward expansion. Brown, in his writings, 

 says that '' by long-continued pressure on the frog 

 in draught horses, and conveyed from the frog to 

 the cartilage, inflammation is set up and the car- 

 tilages turned into bone, viz., sidebone." In this 

 I differ with him, and am of opinion that the 

 more the horse treads upon the frog the better 

 the foot becomes by the attrition. I do not 



/ believe that any horse ever had sidebone by 

 treading upon the frog. I believe that he may 

 have them by his heels being elevated by a thick 

 shoe, and all the natural pressure taken off the 

 frog and thrown upon the bars and crust, and by 

 the frog being cut away to make its feet look 

 nice, as if Nature was not in itself perfection. 

 From inferior and posterior sides of the true 

 cartilages, two fibro-cartilaginous processes ex- 

 tend in a forward direction towards the heels of 



\ the cofiin-bone. They spread inwards upon the 



