CONFORMATION 



165 



above-mentioned splints, do not extend the whole length 

 of the cannon-bone, but diminish to a point before reaching 

 the fetlock. The cannon-bone articulates at its lower 

 extremity with the upper pastern (Plate VI., o), and 

 together they form the fetlock-joint (n) ; and at the back 

 of it are situated two small supplementary bones, termed 

 sessamoids (w), which serve to protect the joint, and also 

 some important ligaments which pass over it. 



PLATE VI. 

 Bones comiected ivith the Foot. 



Pig. 1. 



Pig. 2. 



Ti Cannon, or Shank. 

 m Sesamoids. 

 n Fetlock-joint, 

 o Upper pastern. 

 p Coffin-bone. 

 q Lower pastern. 

 r Navicular-bone. 



The toe is formed by the coffin-bone (p), which is so 

 surrounded by the horny covering of the hoof that it is 

 never visible externally. Another little bone entirely hidden 

 in a like manner is the navicular-bone (r), which lies behind 

 and partly within the junction of the lower pastern and 

 coffin-bone. A very important tendon passes over it, 

 previous to being attached to the coffin-bone, and an injury 

 to the tendon not infrequently affects the navicular-bone 

 also from the accompanying inflammation. Immediately 

 below the navicular-bone is situated the sensible portion of 

 the frog, which again is protected by the horny frog. 



