ANATOMY OF THE HORSE. 
311 
The Sole. 
The sole is the arched plate entering into the formation (as its 
name s implies) of the bottom of the hoof: or, to adopt SainbePs 
definition, “ it is that part which covers the whole inferior sur¬ 
face of the foot, excepting the frog.” It is a very just practical 
observation of Mr. Coleman’s, that although a knowledge of 
every part of the foot is indispensably necessary to render us 
scientific overseers of the farrier’s art, no individual part re¬ 
quires such undivided attention, as regards shoeing, as the sole, 
since the success of this mechanical operation mainly depends 
on the paring and defence of this arched horny plate. 
Situation and Connexion. —It fills up the interspaces between 
the outer and inner walls (or bars) of the crust. I differ in 
opinion from those who describe it to surround the toe of the 
frog. I hold its circumferent support and connexion to be 
entirely the wall of the hoof, to which it is firmly cemented by 
an interstitial horny matter, filling the crevices between the 
laminae. 
Figure. —The circumferent outline of the sole measures about 
two-thirds of a circle, the remaining third being omitted to form 
a triangular-shaped hiatus or opening for the reception of the 
frog and bars. This cleft, or notched circle, however, is by no 
means true, or even invariably the same, in its dimensions. 
Generally, the longitudinal exceeds the transverse diameter. 
Its greatest diameter is shown by a line extended from either 
heel across its middle to the opposite point of the toe. 
Arch. —Commonly, the sole presents an arch of more or less 
concavity inferiorly, and convexity superiorly. But it is not a 
regular or uniform arch, being one that rather waves or undu¬ 
lates, so as to bear a comparison, made of it by Mr. Clark, 
“ to the mouth of a bell extremely extended or flattened.” Like 
that of the bell, the arch is highest in the middle, from which 
it slopes laterally down to a flat, subsequently to rise again 
around its border, in order to present a dilated surface for attach¬ 
ment towards the wall. There is, however, vast variety in the 
degree of arc of the sole: in some feet it is of surprising depth ; . 
in others, the arch is converted into a flattened surface, and yet 
both seem to perform equally well. In the hind feet the sole is 
generally more arched than in the fore, and approaches in figure 
nearer to the oval than the circle. 
Division. —In the sole we distinguish an anterior part or toe; 
a middle or central part; two points or heels ; and two surfaces. 
These divisions are not very well defined : but they prove ser¬ 
viceable in aid of our descriptions. The toe o( the sole is the 
