178 SHOEING. 



The whole inner surface of the horny crust, from the centre 

 of the toe to the point where the bars meet, is everywhere lined 

 with innumerable narrow, thin, and projecting horny plates, 

 which extend in a slanting direction from the upper edge of the 

 wall to the line of junction between it and the sole, and possess 

 great elasticity. These projecting plates are the means of 

 greatly extending the surface of attachment of the hoof to the 

 coffin bone, which is likewise covered by a similar arrangement 

 of projecting plates, but of a highly vascular and sensitive cha- 

 racter ; and these, dovetailing with the horny projections 

 above named, constitute a union combining strength and elas- 

 ticity in a wonderful degree. 



The horny sole covers the whole interior surface of the foot 

 excepting the frog. In a well-formed foot it presents an arched 

 appearance, and possesses considerable elasticity, by virtue of 

 which it ascends and descends, as the weight above is either 

 tsuddenly removed from it, or forcibly applied to it. This de- 

 scending property of the sole calls for one especial consideration 

 in directing the form of the shoe ; for, if the shoe be so formed 

 that the horny sole rests upon it, it cannot descend lower; and 

 the sensitive sole above, becoming squeezed between the edges 

 of the coffin bone and the horn, produces inflammation, and 

 perhaps abscess. The effect of this squeezing of the sensitive 

 sole is most commonly witnessed at the angle of the inner heel, 

 where the descending heel of the coffin bone, forcibly pressing 

 the vascular sole upon the horny sole, contuses a small blood- 

 vessel, and produces what is called a corn, but which is, in fact, 

 a bruise. 



The horny frog occupies the greater part of the triangular 

 Bpace between the bars, and extends from the hindermost part 



