THE PASTERNS. 



249 



io obviate concussion. They have their origin from the head of the shank- 

 bone, and also from the heads of the spUnt-bones ; then descending down 

 the leg, they fill the groove between the splint-bones, but are not attached 

 to either of them ; a little lower down they expand on either side, and, ap- 

 proaching the pasterns, they divide, and are inserted into two little bones 

 found at the back of the upper pastern, one on each side, called the sessa- 

 moid bones. (See p. 63, and in this cut which represents the pastern and 

 foot, sawn through the middle.) They form a kind of joint both with the 

 lower head of the shank-bone, and the upper pastern-bone, to both of 

 which they are united by ligaments (J, and g), but much more closely tied 

 to the pastern than to the shank. The flexor tendons pass down be- 

 tween them through a large mucous bag to relieve them from the friction 

 to which, in so confined a situation, they would be exposed. This liga- 

 ment is continued over the sessamoids, and afterwards obliquely forward 

 over the pastern to unite with the long extensor tendon, and downward to 

 the perforated tendon, which it surrounds and fixes in its place, and also 

 to the smaller pastern bone. 



M i41 



a The shank-bone. 

 h The upper and larger pastern-bone. 

 c The sessamoid-bone. 

 d The lower or smaller pastern-bone. 

 e The navicular or shuttle-bone. 

 / The coffin-bone or bone of the foot. 

 g The suspensory ligament inserted into the sessamoid-bone. 



h A continuation of the suspensory ligament inserted into the smaller pasteru-bone. 

 i The small inelastic ligament, tying down the sessamoid bone to the larger pastern- 

 Done. 



k A long ligament reaching from the pastern-bone to the knee. 



/ The extensor tendon inserted into both the pasterns and the coffin-bone. 



