18 



ANATOMY AND PHYSIOLOGY OF 



" Form. — Sainbel viewed the foot as 

 ' the segment of an oval, opened at the 

 back, and nearly round in front.' To a 

 common observer, the hoof exhibits a conoid 

 form ; tlie part resting upon the ground 

 being the basis, the vacuity above, the ob- 

 truncated apex. IVIr. Bracy Clark asserts 

 that this view is incorrect, and that the 

 general figure of the hoof is a cylinder^ 

 very obliquely trmicated upon its ground 

 surface. This he demonstrates in two 

 ways ; either by rolling up a piece of paper 

 into the shape of a cylinder, and afterwards 

 cutting one of its ends in a very slanting 

 direction ; or by taking a carpenter's square, 

 and placing one limb beneath the foot 

 across the quarters, then sloping the other 

 backward against the side of the quarters, 

 parallel to the front, when the edge of the 

 iron will be found parallel to the wall of 

 the hoof. This corrected view of its figure 

 will serve to account for the general equi- 

 formity manifest in the hoof, and also for 

 the undeviating correspondence found to 

 exist between its slope or slant, as well in 

 front as behind, which in an ordinary or 

 healthy foot may be estimated at an angle 

 of 45*^. Around the coronet, where the 

 hoof unites with the skin, the cylinder is 

 cut directly across its perpendicuJar — at 

 right angles with it : it is the oblique trun- 

 cation of its ground-surface that occasions 

 the slant, which latter we may consequently 

 increase at pleasure by any means that 

 augment the former, viz. : by lowering the 

 heels ; by cutting away a prominent frog ; 

 or by putting on thin-heeled shoes. At the 

 same time that we increase the slant of the 

 hoof, we increase the obliquity of the pas- 

 terns, and likewise proportionately augment 

 the ground-surface of the hoof, from heel to 

 toe, the breadth remaining unaltered ; and 

 in the same ratio, consequently, extend the 

 surface of tread.* 



" Spread. — By the spread, is meant the 

 inclination the hoof manifests, when left 

 unshod, around the toe and sides, to bulge 



* For further elucidation on the cylindrical form of the 

 foot, consult Rlr. Bracy Clark's works on the Foot of the 

 Horse. 



or protrude at bottom, whereby its ground- 

 surface becomes augmented, particularly 

 around the outer quarter. To a certain ex- 

 tent this is worthy of observation ; although, 

 in my opinion, it is to be regarded rather as 

 an effect of pressure than one of abstract 

 growth. The surface of inclination upon 

 which the horn is produced has no such 

 spread, nor can the hoof itself be said, from 

 growth alone, to have any such natural ten- 

 dency; but, as it continues to grow and 

 shoot beyond the inner foot that produced 

 it, and to which it was so intimately united, 

 it yields to the pressure of the animal's 

 weight, and bulges or spreads out, and 

 more at the outer side than the inner, in 

 consequence of the pressure tending more 

 in that direction. If we examine a num- 

 ber of hoofs of neglected growth, and con- 

 sequent exuberance and deformity, of va- 

 rious descriptions, we may discover that, 

 in them all, the spread seems to have been 

 the first or incipient deviation from that line 

 of growth viewed as consistent with the 

 health and well-doing of the foot. It is 

 only in the unshod hoof that any spread is 

 found : as soon as the ground-surface comes 

 to be confined by a shoe, pressure can no 

 longer exert its influence to produce such 

 consequences. 



" Mr. Goodwin aptly observes, that ' to 

 take the form of the hoof correctly, we must 

 strip it of its exuberant or superfluous 

 parts, the same as one would pare the su- 

 perabundant growth off" our own nails. 

 The neglect of this necessary preparative 

 has led to a considerable difference of 

 opinion about the natural, healthy, or true 

 form of the ground-surface of the foot. 

 JVIr. Bracy Clark, I conceive, has inclined 

 to the side of error in this particular ; 

 though, in the substitution of the cylin- 

 drical for the conical figure of the entire 

 hoof, he has certainly the advantage of 

 other wnriters. His natural foot is one 

 with great spread to it, much of which 

 the smith would find it necessary to de- 

 prive it of, even on the first shoeing ; and 

 the protuberance of the outer quarter 

 (which Mr. C. points out as an attribute 



