2Q0 THE HORSE. 



nor would thw loot have so secure a hold. Then, if the sole be naturall> 

 hollow, and hollow because it must descend, the smith must not interfert 

 with this important action. When the fool will bear it, he must pare out 

 suflicient of the horn to preserve the proper concavity, a small portion at 

 the too and near the crust, and cutting deeper towards the centre; and 

 he must put on a shoe which shall not prevent the descent of the sole; 

 which not only shall not press upon it, but shall leave sufficient room 

 between it and the sole to admit of this descent. If the sole is pressed upon 

 by the coffin-bone, by the lengthening of the elastic leaves, and the shoe 

 will not permit its descent, the sensible part between the coffin-bone and 

 the horn will necessarily be bruised, and inflammation and lameness will 

 ensue. It is from this cause, that if a stone insinuates itself between the 

 shoe and the sole, it produces so much lameness. Of the too great concav- 

 ity of the sole, or the want of concavity, we shall treat when we arrive al 

 the diseases of the foot. 



THE COFFIN-BONE. 



We proceed to the interior part of the foot. The lower pastern, a small 

 portion of which (see d, page 249) is contained in the horny box, has been 

 already described. Beneath it, and altogether inclosed in the hoof, is the 

 coffin-bone, or proper bone of the foot, (see^, page 249, and d, fig. 1, page 

 253). It is fitted to, and fills the fore part of the hoof, occupying about 

 half of it. It is of a light and spongy structure (see d, fig 1, page 253), 

 and filled with numerous holes. Through these pass the blood-vessels of 

 the foot, which are necessarily numerous, considering the important and 

 various secretions there carrying on, and the circulation through the foot 

 it is plain could not possibly be kept up, if these vessels did not run 

 through the substance of the bone. The holes about the body of the coffin- 

 bone convey the blood to the little leaves with which it is covered ; those 

 near the lower part go to the sole. Considering the manner in which this 

 bone is inclosed in the horny box, and yet the important surfaces around 

 and below it which are to be nourished with blood, the circulation which is 

 thus carried on within the very body of the bone is one of the most beauti- 

 ful provisions of nature that is to be found in the whole of the frame. 

 No inconvenience can arise from occasional or constant pressure, but the 

 bone allows free passage to the blood, and protects it from every possible 

 obstruction. 



The fore-part of the coffin-bone is not only thus perforated, but it is curi- 

 ously roughened for the attachment of the numerous little leaves about to 

 be described. On its .upper surface it presents a concavity for the head 

 of the lower pastei'n, p. 235. In front, immediately above d, is a striking 

 prominence, into which is inserted the extensor tendon of the foot. At the 

 back, e, p. 249, it is sloped for articulation with the navicular-bone, and 

 more underneath, is a depression for the reception of the perforating flexor 

 tendon, m, continued down the leg, passing over the navicular-bone at n, 

 and at length inserted into this bone. On either side, as seen at p. 254. 

 are projections, commonly called the wings or the heels of the coffin-bone, 

 and at the bottom it is hollowed to answer to the convexity of the interna' 

 part of the sole. 



That which deserves most attention in the coffin-bone is the production 

 of numerous little leaves round its front and sides. They are prolongations 

 of the thick and elastic membrane covering the coffin-bone, and consist of 

 cartilaginous, fleshy plates, proceeding from it, running down the coffin 



