HOESE-SHOEING. 141 



This injury is prevented by the coronary, and, to a lesser extent, 

 by the plantar cushion, which largely retard the descent of the 

 bone on the floor of the horny box. 



The frog, on both hard and soft ground, is an essential portion 

 of the weight- bearing face. In the unshod, healthy foot it always 

 projects beyond the level of the sole, and seldom below that of the 

 wall at the heels; indeed, it is found, in the majority of hoofs, 

 either on a level with the circumference of this part, or beyond it, 

 so that its contact with the ground is assured. Hence its utility 

 in obviating concussion, supporting the tendons, and on slippery 

 ground, in preventing falls. In pulling up a horse sharply in the 

 gallop, or in descending a steep hill, the frog, together with the 

 angular recess formed by the bar and wall at the heel of the hoof, 

 are eminently serviceable in checking the tendency to slip ; the 

 animal instinctively plants the posterior portions of the foot ex- 

 clusively on the ground. 



Dark hoofs are generally the best ; they owe their color to the 

 presence of minute particles of black pigment, which contains 

 a notable proportion of iron, and are somewhat resisting and 

 indestructible. 



A good hoof should have the wall unbroken, its outer face smooth 

 and even ; the angle at the front not less than 50°— the lower or 

 ground face of the front hoof should be nearly circular in outline — 

 the sole slightly concave at the circumference, deeper at the center ; 

 the border of the wall ought to be thick at the toe, gradually 

 thinning towards the heels, but at the inflexion or commencement 

 of the bar a strong mass of horn should be found; the bars 

 should be free from fracture, and the frog moderately developed, 

 firm and solid. 



The hind foot should possess the same soundness of horn, though 

 it differs from the fore hoof in being more oval in outline from the 



