REVIEW. 
152 
well as to the greater collision with the branches of the shoes, 
owing to the distribution of the nails around the fore parts of 
the hoof. 
“ Indeed, so far from the brightened places upon the old shoe 
being demonstrative of expansion, they might rather be regard¬ 
ed as shewing how exceedingly limited such expansion must 
be; since, if comparison be made by admeasurement between 
the transverse diameters of the crust of the foot and the bright 
marks upon the web of the shoe, we shall find the most perfect 
equality between them at every point; proving that the play 
elasticity gives to the foot, which is so nice of detection in the 
natural (unshod) foot, is all but annihilated under the ordinary 
conditions of shoeing. Limited however as it is, still it actually 
takes place, as we think has been proved by the demonstrations 
we have here adduced. 
“The force putting into action the expansibility 
OF THE HOOF is derived from the pression within its cavity 
of the coffin-bone, upon which the entire superincumbent weight 
descends.” 
M. Bouley proceeds here to shew the manner in which the 
weight of the body is transmitted, through the bony shafts of 
the limb, upon the foot;—how therein the pression becomes pro¬ 
ductive of a double movement; one being in a direct line with 
the laminae, the other in an oblique line (from before backward 
and from above downward) parallel with the plane of the coffin 
articulatory surface : after which, he enters into a detail of the 
functions of the sole, bars, and frog, as component parts of the 
elastic apparatus; and finally concludes the subject of the 
Elasticity of the Hoof” by coming to the annexed deductions:— 
“ 1. That the hoof, considered as a whole, is not completely 
immutable in form; but, on the contrary, is capable, in a 
degree very limited it is true, but still real, of yielding to the 
pression of internal force, and of recovering, on the cessation of 
such force, its primitive form ; and this it is that constitutes its 
elasticity. 
“ 2. That this elasticity is especially manifest in the posterior 
part of the hoof, where the wall exhibits a breach in its con¬ 
tinuity, which is occupied by the more pliable horn of the heels 
of the frog and by the arciform plates of the periople (coronary 
frog-band). 
“3. That it (the elasticity) is put into play, at the moment of 
appui, by the aggregate of pression transmitted down the pas¬ 
terns upon the pedal bones. 
