22 



ANATOMY AND rHYSIOLOGY OP 



as mules and asses, have vpright or strong^ 

 feel (i. c), walls but moderately sloped; 

 wiiercas heavy horses, cart-horses, and 

 coach-horses, have commonly Jlat or weak 

 feet (i. e.), walls that slant immoderately. 

 And (as was before observed) upon the 

 degree of obliquity of the wall must very 

 much depend that of the pasterns. In esti- 

 mating the slant or slope of the wall, it is 

 proper to distinguish between that which is 

 consequent on the detruncation of the hoof, 

 and such as is the effect of a burthen under 

 which the wall succumbs. The depth of 

 horn in front of the toe, measuring from the 

 termination of the skin to the most promi- 

 nent point below (and supposing the hoof 

 to be cut and ready to receive the shoe), 

 may be rated at about three and a half 

 inches. The bow or degree of convexity 

 of the toe in front must depend upon its 

 obliquity as well as upon the circularity of 

 the foot. The thickness of the horn com- 

 posing the toe may be estimated at three- 

 eighths of an inch, or from that to half an 

 inch, and this substance is the same from 

 immediately beneath the coronary circle to 

 the junction of the wall with the sole ; at 

 which part there is an accession of horny 

 matter to block up the interstices bet\veen 

 the laminae, and also to fill the angular 

 vacuity that would otherwise exist here 

 between the wall and sole. In the fore-feet, 

 the toe is thicker in substance than either 

 the quarters or heels ; but (we have it from 

 Sainbel) ' in the hind, on the contrary, the 

 heels and quarters are generally thicker than 

 the toe.' 



" The Quarters are the portions of the 

 wall intermediate between the toe and the 

 heels. They are commonly described as 

 standing upright^ and, according to a car- 

 penter's square set against the wall, so they 

 appear to do ; this is not, however, the view 

 the anatomist ought to take of their posi- 

 tion : to him the oblique course of their 

 component fibres, together with the slant of 

 their lamina?, demonstrate that they slope 

 in the same manner and degree as the toe 

 does. The quarters do not run in straight 

 lines from before backward, but by their 



prominence describe gentle curves, the outer 

 making a wider sweep than the inner. 

 This gives the hoof altogether a sort of 

 livisted appearance, and makes the inner 

 part of the toe look more projecting than 

 the outer; a deviation that seems principally 

 to have originated in the spread, and one, 

 methinks, that has had more attention given 

 it than any consequences attachable to it 

 render it deserving of. The quarters range 

 in depth from two to three inches; and 

 measure in thickness from one-fourth to 

 three-eighths of an inch. 



" The Heels are the two protuberant por- 

 tions of the wall by which it is terminated 

 posteriorly. They are the shallowest, and 

 thinnest, and {in connection) only flexible 

 parts of the wall. Though their surfaces 

 recede from the perpendicular, they main- 

 tain the same slope as the toe and quarters. 

 At their angles of inflection, from which 

 are continued the bars, they form (in con- 

 junction with the heels of the sole) pouches 

 or sockets into which are received the heels 

 of the sensitive foot. In depth they range 

 from one and a half to two inches. In sub- 

 stance they do not exceed a quarter of an 

 inch, the outer heel being rather thicker than 

 the inner. 



" The Superior or Coronary Border is the 

 circular, attenuated, concavo-convex part 

 entering into the composition of the coronet. 

 Its extent is marked exteriorly by the whitish 

 aspect it exhibits, and also by some partial 

 separation and eversion of the outer flakes 

 of horn around its junction with the wall 

 below. Externally, it assumes the same 

 character as the wall below it ; but its in- 

 ternal surface is altogether different. In- 

 stead of possessing lamina?, the surface is 

 smooth and uniformly excavated, being 

 moulded to the form of the sensitive coro- 

 net, and ever3rvvhere presenting numerous 

 pores for the purpose of receiving the secret- 

 ing villi. Superiorly, tlie coronary border 

 presents two edges, having a groove be- 

 tween them for the reception of the termi- 

 nating border of the cutis. It is this groove 

 that marks the reception of the coronary 

 border into two parts: the internal edge 



