256 MANUAL OF MODERN FARRIERY. 



and deep, and of a triangular form, bounded on the sides by 

 sloping prominences, which diverge from the convexity forni- 

 ina- the toe of the frog, and terminate at the lieels. Tlii? 

 cavity is called the cleft of (he frog. 

 <r. The frog, as also exhibited fig. 12, d, d. In its superior sur- 

 ■ face it is continuous, uniform, and porous, being the counter- 

 part in form of the inferior surface, presenting only reverses, 

 where the one is hollow, and the other swelling. Opposite to 

 the cleft is the frot/sfay, which is elevated and bounded on its 

 sides by two deep channels, and a hollow of shallower dimen- 

 sions in the front. This bold, horny elevation is admirably 

 calculated to form that dove-tailed connexion with tlie sensitive 

 foot, which greatly augments their surfaces of opposition, and 

 establishes their union beyond all risk or possibility of dis- 

 location. 

 h, h. The external crust, or wall; as also seen fig. 12, a, «., and 

 fully described above. At the first h and i is the rounded 

 portion of the heels belonging to the frog. 

 /, Fig. 12, is the external surface of the sole, or the arched plate 

 entering into the formation of the bottom of the hoof, and cover- 

 ing the whole inferior surface of the foot, excepting the frog. 

 No individual part requires such undivided attention as the 

 sole, as regards shoeing ; since the success of this mechanical 

 operation chiefly depends upon the paring and defence of this 

 arched horny plate. Viewed from below, the sole commonly 

 presents an arch of more or less concavity. It is subject to 

 vast varietv in the desrree of the arc ; in some feet it is of 

 surprising depth, and in others the arch is converted into a 

 flattened surface, and yet both seem to perform equally well. 

 In the hind feet the sole is generally more arched than in the 

 fore, and approaches in figure more to the oval than the circle. 

 Its thickness is about one-sixth of. an inch. That portion 

 most elevated from the ground — that which forms a union 

 with the bars — is nearly double the thickness of the central or 

 circumferent parts, and next to this in substance comes the 

 heel. This is situate at the back part of the foot, at which 

 point the crust of the hoof, instead of being continued round 

 and forming a complete circle, iS abruptly bent in, as ^jl] be 

 seen by a reference to fig. 12, and at h, fig. 11 



