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

84 The Management and Treatment of the Horse,
rising of the frog. The preservation and usefulness of
the limbs of the horse are chiefly maintained by this
upward expansion. Brown, in his writings, says
that "by long-continued pressure on the frog in
draught horses, and conveyed from the frog to the
cartilage, inflammation is set up and the cartilages
turned into bone, viz., sidebone." In this I differ with
him, and am of opinion that the more the horse treads
upon the frog the better the foot becomes by the
attrition. I do not believe that any horse ever had
sidebone by treading upon the frog. I believe that he
may have them by his heels being elevated by a thick
shoe, and all the natural pressure taken off the frog
and thrown upon the bars and crust, and by the frog
being cut away to make its feet look nice, as if Nature
was not in itself perfection. From inferior and
posterior sides of the true cartilages, two fibro-car-
tilaginous processes extend in a forward direction
towards the heels of the coffin-bone. They spread
inwards upon the surface of the tendo-perforans,
become united at their inner sides with the superior
margin of the sensitive frog, are covered inferiorly by
the sensitive sole, and at the same time assist in the
support of the sensitive frog. They are triangular in
form and are arched in the same manner as the sole.
Their use appears to be to fill up the triangular vacant
spaces left between the tendo-perforans and the
heels of the coffin-bone, thereby completing the surface
of support for the frog, and extending that for the
expansion of the sole. The navicular bone is a small
bone resembling a weaver's shuttle and has a side-to-