The Foot — lis Description. 103 



of the hoof, instead of being continued round 

 and forming a complete circle, is abruptly bent 

 in. The next in importance to the lamella of the 

 horse's foot are the cartilages. The cartilages 

 are two broad scabrous concavo-convex cartila- 

 ginous plates which surmount the sides and 

 wings of the coffin-bone. There is a groove 

 extending along the upper part of the coffin- 

 bone on each side, except at the protuberance 

 which receives the extensor tendon, and which 

 extends to the very posterior portion of the foot^ 

 rising at the quarters fully half an inch above 

 the hoof, and diminishing in height backward 

 and forward. These cartilages occupy a greater 

 portion of the foot than the coffin-bone, which 

 they extend far behind, and are fixed into two 

 grooves excavated into the superior lateral 

 borders of the coffin-bone, the navicular bone, 

 and the flexor tendon, and are thus perfectly 

 secured. Below these are other cartilages con- 

 nected with the under edges of the former, and 

 on both sides of the frog. Between these car- 

 tilages is the sensitive frog, occupying the whole 

 of the space, and answering several important 

 purposes, it being an elastic bed upon which the 

 navicular bone and. the tendon can play with 

 security, and without concussion to the cartilages. 

 By this means all concussion to the cartilages 

 of the foot is prevented, the cartilages kept 

 asunder, and the expansion of the upper part 

 of the foot preserved. This mechanism is both 

 beautiful and important. The yielding and elastic 

 substance of the frog is pressed upon by the 



