REVIEW.—ON THE CONFORMATION OF THE HORSE. 91 
has been estimated that, so disposed, the laminse increase twelve 
times the adhesion between the hoof and the foot. The following 
example will give us a just notion of this:—Take a book of a 
certain thickness, endeavour to paste or glue it to another of the 
same size, by as much of the surface of its leaves as is exposed 
when close shut: the surface of cohesion being so limited, little 
force would be required to separate one book from the other. But, 
now open the leaves of the two books, and serve them as Nature 
has the laminse of the horse’s foot. Separate the leaves of the two 
books, and dove-tail them, one set into the other, and in that posi¬ 
tion paste them together. United in this manner the separation of 
the two books becomes impossible, in consequence of the multipli¬ 
cation of the surfaces stuck together. The wall being flexible and 
disposed after the manner of an arc, so contributes to the elasticity 
of the foot. Thus are the three uses of the wall completed. 
“ The sole is likewise flexible, and is disposed in the form of an 
arch, in order that it might with more effect resist the superincum¬ 
bent weight, the tendency of which is to press it close to the 
ground. The moment it is pressed, therefore, it bends, and its 
borders being in close union with the wall, that opens and closes 
under its pressure, after the manner of a bow. If the arc of the 
sole remained fixed, if it no more returned after being pressed 
down to its natural shape, the action of the bow would not be sus¬ 
tainable : the Maker thereof would have strangely defeated his 
own end, and that can but seldom happen. Therefore, the sole, 
like the wall, contributes to the protection of the foot, to consolidate 
the union between it and the hoof, and to render the whole elastic. 
“ The texture of the frog differs essentially from those of either 
the wall or the sole. Its substance, soft and flexible, in action 
possesses great analogy to elastic gum. It yields to pressure, and 
resumes its form after the same manner the moment pressure is 
abstracted. It often happens that this wedge, squeezed by the 
superincumbent weight against hard ground, spreads and dilates 
the interspace it occupies. The incurvated extremities of the bow 
formed by the wall being fixed to the frog, are forced farther apart 
every time the frog is expanded by pressure upon an unyielding 
surface. Bracy-Klarc (Bracy Clarke) holds a different opinion. 
According to him the frog constitutes the veritable chord of an arc 
to the wall. In general, we are willing to admit this theory; at 
the same time, it appears to us impossible to deny the forced ex¬ 
pansion of the frog as the plantar cushion, and especially whenever 
the appui is against a hard substance. And if we are compelled 
to admit such expansion, can we deny its influence in dilating the 
heels'! We put this question to physiologists.” 
