244 
MANUAL OF MODERN FARRIERY. 
horses are entrusted. In ordinary action this joint has 
heavy work to perform, but often more severe exertion is 
exacted from it than even its admirable construction can 
possibly perform. Much of the lameness of the hind 
quarters will be found, upon careful examination, to be 
seated in the hock. If the exact locality of lameness 
cannot be detected elsewhere, we may almost consider that 
it is somewhere connected with the complicated structure 
of the hock-joint, and we may particularly refer to the 
various diseases of this joint described towards the begin¬ 
ning of chapter vi., page 130 
BONES OF THE FOOT. 
PLATE VI. Fig. 3. 
This figure represents a back view of the bones of the 
pastern-joint and of the foot, and those connect*! with it. 
The coffin-bone constitutes its osseous fabric, to which the 
navicular bone may be regarded as an appendage. The 
anatomy of this part should be well understood, as it is of 
much importance in the action of a horse, as also very liable 
to disease. 
a. The coffin-bone, with its horny laminae. It is situated within 
the hoof, which it nearly resembles in form, being in its outline 
crescent-shaped. Its form, however, varies With the natural 
make and morbid changes in the form of the hoof. The coffin- 
bone is ot a soft spongy texture. 
b. The navicular-bone, or shuttle-bone, which is situated at the 
back of the coffin-joint, into whose composition it enters. It 
is crescent-shaped. One of its extremities is directed out¬ 
ward, and the other inward; their points are obtuse, and are 
fixed by lateral ligaments to the coffin-bone. 
c. The lower pastern, or coronet-bone. Its situation is between 
the pastern and the foot, and answers to the second phalanx of 
the human foot. Its form is nearly square, 
d. The upper pastern is situated below the cannon-bone, 
