734 SHOEING. 



toe (Fig. 189, p. 735). If the toe be too long, but the heels of right 

 height, the toe should be lowered in a straight line to the heels, 

 which should not be touched (Fig. 190, p. 735) ; and vice versa. 



VTeight-bearing Surfaces of the Foot. 



The horn of the wall, sole, frog and bars is secreted by a 

 membrane (sensitive laminae) which covers a portion of the pedal 

 bone and soft structures of the foot, like a sock ; while the hoof 

 acts the part of a boot. As this membrane is highly sensitive ; the 

 ground surface of the foot is constructed so that the necessary 

 weight-bearing points may be obtained without injury to it. With 

 this object, that portion of the sole immediately underneath the 

 pedal bone, which is protected by hard horn, is constructed in the 

 form of an arch ; for were it level, the membrane would, at every 

 step, be in danger of becoming pinched between these two hard 

 substances — ^the sole and the pedal bone. The weight>bearing 

 surfaces, therefore, are as follows : — (1) the ground surface of the 

 wall and that portion of the sole not directly underneath the pedal 

 bone (see o & on right-hand side of Fig. 191, p. 736) j (2) the frog, 

 which is endowed with elasticity, and can consequently bear 

 pressure without getting its secreting membrane hurt; (3) the 

 bars, which are continuations of the wall. We may readily see that 

 the weight-supporting functions of the frog, outer portion of the 

 sole, and bars, should be fully utilised ; for if the wall alone be 

 subjected to concussion, the resulting strain on that portion of the 

 secreting membrane which the wall covers, namely, the sensitive 

 laminae, may become so excessive, that laminitis may ensue. The 

 weight-bearing surface at the toe is far broader than at the heels 

 (Fig. 72, p. 217) ; for the slope of the foot is less, and the thickness 

 of the wall greater, at the former, than at the latter. That 

 portion of the sole — "the seat of corn" (Fig. 73, p. 221) — which 

 lies in the angle formed by the wall and the bars, should on no 

 account bear weight ; because a part of the pedal bone is im- 

 mediately above it, and the sole which covers it is very thin. 

 Consequently the secreting membrane above it, is particularly 

 liable to injury. 



Examine the worn shoe of a normal fore foot, and it will be 

 found that it has sustained the greatest amount of wear a little to 

 the outside of the toe and not in the exact direction of the long 

 axis of the foot. In fact, the outside half of a normal fore foot 

 sustains more wear than the inside half, an inference which might 

 be drawn from the fact that the horn of the former is thicker than 

 that of the latter. 



In order to meet the wear and tear to which the foot is sub- 



