74 



THE PROTECTIVE STRUCTURES OF THE FOOT. 



occurring alone the row of cells from which the inner portion 



of the horny capsule is developed. 



The hoof may be divided into three different parts, which, 



however, though differ- 

 ing from one another 

 in essential particulars,, 

 must, on account of 

 their position and func- 

 tion, be looked on as 

 three parts of one and 

 the same structure. No 

 one of these portions can 

 be removed without in- 

 iury to all and without 



Fig. 44. — Hoof with vascular st)uctiues removed, a, '' . . 



periople; owing to maceration ill water this is swollen weakcuin^'' all. iheU' 



and prominent; the outer border exhibits adherent , .,..., .5^ 



hairs, the inner fine punctations. Towards the heels mdlVlSlbllltV and UlUtU- 

 («') the periople is seen to broaden out and become . " 



continuous with the horny buiijs. At a" a portion of al interdependence are 



horn has been removed. From the point to h consti- i i i 



tutes the toe, from 6 to c the quarter, and from c to d bcst UUdcrstOOd by CarC- 

 the heel of the foot ; e, projecting portion of frog ; /, -u • 



coronary furrow or cutigeral groove, showing numer- f ully regarding the lU- 

 ous punctations ; n, laininal sheath of wall. . ^ ^ e e 



tenor or a hoot arter 

 removal. At no point can sharp divisions be recognised ; each 

 part unites and becomes continuous with the other. The three 

 parts of the hoof are wall, sole, and frog. 



1. The Horky Wall 



Is that part of the hoof which is visible when the horse is 

 standing (fig. 44), and which protects the foot in front and on 

 either side. If we compare the foot with a man's shoe, the 

 wall represents the upper, though, with this difference, that it 

 extends down to the ground and embraces the sole. 



The horny wall exactly responds both in position, course,, 

 and direction, as well as in the combination of its various 

 parts, to the sensitive structures that produce it. It extends 

 obliquely downwards from the border of the skin, decreasing 

 in length (or height) towards the back. At the heels it 

 bends inwards at either side (compare figs. 45, 46, and 47), 

 runs for a short distance in a forward direction, and gradually 

 becomes lost in the sole. The horny wall, therefore, does not 

 surround the foot like a riuQ-, but its extremities are infolded 



