434 PLANTAR SYSTEM. 



increasing in thickness, gradually rejDresents sole and frog. Not, 

 however, in an undeveloped state ; for even at birth, these parts 

 are yet concealed by the exuberant cuticular covering, now 

 become loose in its texture, and shaggy and ragged, in conse- 

 quence of not receiving any further supply from the parts that 

 produced it, and of being near its decadence ; for it not long after 

 falls off, disclosing sole and frog, both ready formed. 



Structure ojthe Hoof. 



Horn is found to differ in its texture or quality, not only in the 

 many animals in which it is met with, but in different parts, and 

 even in the same part of the body of the same animal. That 

 which composes the hoof of the horse is a remarkable example 

 of this. How different is the horn of the frog from the horn 

 of the wall ; and yet neither of them agree in texture with the 

 sole. The horny substance of the wall is resolvable into fibres, 

 bearing a resemblance to thick or coarse hairs, which in the 

 entire hoof are so intimately matted and glued together, as to 

 have the appearance and strength of solidity. By close and 

 accurate inspection these fibres may be seen, descending in paral- 

 lel lines, taking the obliquity of the wall, from the coronet to 

 the inferior or solar border : they do not run promiscuously, but 

 are arranged in rows, forming sorts of beds or strata, lying one 

 upon another — a disposition made manifest in the foot of the 

 foetus. A clean-cut transverse section of the wall exhibits upon 

 its surface numerous minute, circular, whitish spots, which grow 

 larger and more distinct towards the internal part, and through a 

 glass appear to be hollow or tubular. These spots I take to be 

 produced by section of the horny tubes, apparently containing a 

 whitish matter, a sort of pith, or pulp, or gelatinous instillation 

 which pervades them from their origin from the villi of the coro- 

 nary circle ; the same as hairs derive their unctuous matter from 

 the bulbs producing them, and (as this matter does the hair) 

 renders the horny fibre tough and elastic — in fact, embues it with 

 the peculiar attributes so well known to smiths by the appellation 

 of living horn ; the epithet "living " being here used to denote 

 the obvious differences the hoof of a living animal evinces from 

 one that has been long detached from the body, or that is dead. 

 We are too apt to believe that the various agents known to act 

 upon the dead hoof or horn must take similar effect on the living ; 

 and upon this erroneous belief we employ hot and cold water, &c. 

 &c. in treating disease of the feet, forgetting that we have 

 opposed to our remedies the resisting or self-preserving properties 

 of living horn. 



