The management and treatment of the horse in the stable, field, and ...

In the Stable, Field, and on the Road. 83
each side, except at the protuberance which receives the
extensor tendon, and which extends to the very posterior
portion of the foot, rising at the quarters fully half-an-
inch above the hoof, and diminishing in height backward
and forward. These cartilages occupy a greater portion of
the foot than the coffin-bone, which they extend far behind,
and are fixed into two grooves excavated into the superior
lateral borders of the coffin-bone, the navicular bone, and
the flexor tendon, and are thus perfectly secured. Below
these are other cartilages connected with the under edges
of the former, and on both sides of the frog. Between
these cartilages is the sensitive frog, occupying the whole
of the space, and answering several important purposes,
it being an elastic bed upon which the navicular bone
and the tendon can play with security, and without con-
cussion to the cartilages. By this means all concussion
to the cartilages of the foot are prevented, the cartilages
kept asunder, and the expansion of the upper part of the
foot preserved. This mechanism is both beautiful and
important. The yielding and elastic substance of the
frog is pressed upon by the navicular bone, as well as by
the tendon and the pattern, and being incapable of con-
densing itself into less compass is forced out on each side
of them and expands the lateral cartilages. These again
by their inherent elasticity revert to their former situa-
tion when they are no longer pressed outward by the frog.
It thus appears that by a different mechanism, but
both equally admirable and referable to the same
principle of elasticity, the expansion of the upper and
lower parts of the hoof are affected ; the one by the
descent of the sole and the other by the compression and