PATHOLOGICAL CONDITIONS OF FEET. 



816 



the convex form of the plantar surface of that bone had, as is always 

 the case, its counterpart in the form of the hoof, the sole of which 

 Avas pawmace— after a French expression, — literally, apple-shaped, 

 or round instead of concave and arched. But the t3q:)ical character 

 of those coffin-bones, as represented by the sing-le specimen, is that 

 of both being fractured in a transverse direction across the bottom 

 of the bone, at an inch from the point. 



Fig. 720 shows the foot, drawn as it was placed upon a table, 

 and will help in this 

 description the com- 

 prehension of the state 

 of the case. The point 

 of the bone is turned 

 up. The bone, which 

 hadbecome shallow and 

 weak, at length, under 

 the weight and exer- 

 tion of the animal, gave 

 way at the part indi- 

 cated, i. e., it fractured, 

 but was held together 

 by the net-work of fi- 

 bious texture which 

 laces and invests the 

 bone. The lesion may 

 be regarded as a partial 

 fracture, associated 

 with a bending upward 

 of the loosened end of 

 the bone, held in prox- 

 imity chiefl}'^ by the fi- 

 brous tissues, but sup- 

 ported also by the hoof, which, though thiimed and weak, took the 

 form of the broken bone, and was bent upward in front. The 

 other foot I prepared, differently from that used for these en- 

 gravings, by sawing longitudinally through the hoof and the in- 

 cluded parts while fresh; these, together, are remarkable sjjecimens. 



Fig. 721 represents another form of fracture of a coffin-bone, but 

 though differing in its appearance, and place of the occurrence of 

 fracture, from the case previoiisly described, the two help to eluci- 

 date each other as to the cause and mode of occurrence. As shown 

 by the engraving, this bone was flattened down by absorjjtion until 

 it became so attenuated as to be unequal in substance and strength 

 to bear the burden imposed, and it therefore gave way under it. It 

 will be observed that the bone broke where, from greatest pressure 

 and absorption, it had become weakest, and, as in the former case, 

 it broke where the greatest strain of lever action was brought to 

 bear upon it. To explain, I must state that the coffin-bone is one 

 of the most energetic levers in the whole system of animal-con- 

 struction, in the line of its long axis from heel to point. The fract- 



FiG. 721. 



