THE HORNY SOLE. 



85 



or are removed in shoeing, so that the sole never exhibits the 

 smoothness of the wall, but has a rough, uneven appearance. 

 The detached pieces are often so changed that they can readily 

 be reduced to a pulverulent mass, nor does even the newly- 

 formed horn close to the sensitive sole exhibit the firmness of 

 the horny wall ; it can easily be cut with a knife, and permits 

 of foreign bodies, like nails, penetrating much more easil}' than 

 that of the wall. The horny frog and bars complete the under 

 surface of the foot. They are inserted into the triangular, 

 wedge-like space which the sole exhibits towards the baclv, and 

 which divides it into an anterior continuous part, termed the 

 body (figs. 45 and 46, /), and two posterior parts, separated 



ce — 



# 



Fig. 51. 



Fig. 



Fig. 51. — Vertical trausverse section of hoof with very thin sole, a, periople, continued over 

 the entire wall as indicated by a': b, middle sheath, showing at b' its white tint ; c, lami- 

 nal sheath; (7, union between laniinal sheath and sole (white line); e, sole (excessively 

 trimmed) ; /, point of frog ; </, space occupied in life by pedal bone and vascular 

 structures. 



Fig. .'i2. — Left lower part of above section (natural size), a, middle sheath : b, laniinal sheath, 

 continued as far as the ground surface ; c, sole ; d, yellow soft tubular horn between wall 

 and sole, to be found also between the individual laniiiiic. 



by this space, the branches or wings of the sole (figs. 45 and 



46, ./■')• 



The sole presents an upper and a lower surface, an anterior 



semicircular and a posterior indented border, as above noted. 



The upper surface is convex (fig. 51, e) and lies in contact with 



the sensitive sole. The highest part is above the point of the 



horny frog (/) ; whence it slopes downwards towards the wall 



both in front and at the sides, rising again, however, to a slight 



extent in tlie immediate vicinity of the wall. 



. Exactly in the middle line of the toe, where the sole joins 



the wall, is a small but distinct prominence (fig. 48, i), which 



extends on to the wall and corresponds to the excavation in the 



