the forge will best guard
against this by viewing the foot, while on the ground, from behind. From
that position he will be able to detect the lowness of the quarters, and
the projecting portion of the shoe, that the hoof, by reason of its sudden
bending inwards, does not touch.

The 'feeling' manner of the gait before alluded to, together with the
disinclination to put the foot firmly and squarely forward, will sometimes
lead the examiner to over-look the contraction, and diagnose his case as
one of shoulder lameness. In many cases, too, such consequent conditions
as 'thrushy frogs' and 'suppurating corns' are often treated with utter
disregard of the contraction that has really brought them about. But above
all, the disease most likely to be confounded with simple contraction is
navicular disease. More than probable it is that many cases of so-called
'navicular' have in reality been nothing more than contraction brought
about by one or other of the causes we shall afterwards enumerate--cases
where a due attention to the prime cause of the mischief would, in all
likelihood, have remedied the lameness.

_Changes in the Internal Structures_.--It follows as a matter of course
that the changes we have described in the form of the hoof itself carry
with them alterations in the bones and sensitive structures beneath it. The
tissues, as a whole, become atrophied. The os pedis becomes deformed, loses
its circular shape, and gradually becomes more or less oval in contour.
At the same time, its structure becomes more compact, the cribriform
appearance of its anterior and lateral faces more or less destroyed, and
the few remaining openings apparently increased in size. This atrophy of
the os pedis is best noted at the wings.

In the plantar cushion the effects of the atrophy are noted in the
smallness of the organ, in its becoming whiter in colour than normal, and
more resistant to pressure.

The coronary cushion is also affected in the same way, where the changes
are noted most in its posterior portions.

A further effect of the narrowing of the heels, and their consequent
tendency to drop downwards, is the exertion of a continual pressure on the
sensitive sole. In course of time, and especially in flat feet, this leads
to the appearance of corns.

The navicular bone and bursa and the tendon of the perforans also suffer
from the effects of compression. The movement of the tendon is restricted,
and arterial supply to the ad