BONES AND INTEGUMENTS OF PASTERN AND FOOT. 249 



great pressure, which would occasionally ohstruct its free 

 passage. The upper surface, it will be seen, is concave, for 

 the reception of the rounded end of the lower pastern, b ; at 

 the back, o, is a depression for the perforating tendon, g. We 

 have described the diseases connected with tliis joint at 

 page 125. 



b. The lower or smaller pastern-bone. 



c. The upper or larger pastern-bone. 



d. The shank-bone. 



e. The sesamoid-bone. 



/. The suspensory ligament. See rupture of this described, 

 page 122. 



g. The tendon of the perforating flexor, inserted into the coffin- 

 bone after having passed over the navicular-bone. 



h. A long ligament, reaching from the pastern-bone to the 



knee. 

 i. The small inelastic ligament, which fastens down the sesamoid 

 bone to the larger pastern. 



j. The extensor tendor., inserted into both the pasterns and the 

 coffin-bone. 



k. A continuation of the suspensory ligament, inserted into the 



smaller pastern-bone. 

 /. The navicular, or shuttle-bone. One of the chief uses of this 

 bone is to take off a portion of the weight from the coffin-bone ; 

 and from the navicular-bone it is thrown on the tendon, which 

 rests on the elastic frog beneath. See diseases of this bone, 

 page 165. 



m. The inner, or sensitive frog. This is a wedge-shaped body 

 projecting from the bottom of the foot, together with the sub- 

 stance continued from it, and occupying the interval between 

 the cartilages. 



n. A ligament which unites the navicular-bone to the smaller 

 pastern. 



o. A ligament uniting the navicular-bone to the coffin-bone. 



p. This is the seat of lameness of the navicular joint. 



q. The sensitive sole between the coffin-bone and horny sole. It 

 is placed between the coffin-bone and the sole ; and, from its 

 yielding nature, assists in preventing concussion, and also 

 forms a supply for the horn of the sole. It is furnished with 

 nervous fibres, and is highly sensitive. The lameness which 



2k 



