42 



DISEASES OF THE HORSE'S FOOT 



the external border, and, like it, is dovetailed into the 

 horny laminae of the inflections of the wall — namely, the 

 bars. In front of the termination of the bars it is dove- 

 tailed into the sides and point of the frog. Where unworn 

 by contact with the ground, the horn of the sole is shed by 

 a process of exfoliation. 



3. The Frog. — Triangular or pyramidal in shape, the 

 frog bears a close resemblance to the form of the plantar 



4- ...h|..: 



Fig. 22. — Hoof with the Sensitive Structures removed. 



I, Superior face of horny frog; 2, the frog-stay; 3, the lateral ridges 

 of the frog's superior surface ; 4, the horny laminae at the in- 

 flections of the wall. 



cushion, upon the lower surface of which body it is 

 moulded. It offers for consideration two faces, two sides, 

 a base, and a point or summit. 



The Superior Face is an exact cast of the lower surface 

 of the plantar cushion. It shows in the centre, therefore, 

 a triangular depression, with the base of the triangle 

 directed backwards. Posteriorly, the depression is con- 

 tinued as two lateral channels divided by a median ridge. 



