BONES AND INTEGUMENTS OF PASTERJN AND FOOT. 249 
great pressure, which would occasionally obstruct 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 
nave described the diseases connected with tins 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. 
f. The suspensory ligament. Set rupture of this described, 
page 122. 
g. The tendon of the perforating 1 it>or, inserted into the coffin- 
bone after having passed over the navicular-bone. 
h. A long ligament, reaching from the pastern-bone to the 
knee. 
f. The small inelastic ligament, which fasfens down the sesamoid 
bone to the larger pastern. 
/. The extensor tendon, inserted into both the pasterns and the 
coffin-bone. 
k. A continuation of the suspensory ligament, inserted into the 
smaller pastern-bone. 
l. 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. 
«. 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 
