ANATOMY AND PHYSIOLOGY OF THE FOOT 



435 



Fig. 626.— The Sensitive Foot: Side View 



A, Skin, a', Skin devoid of hairs. B, Peripolic band, 

 c, Coronary cushion. D, Sensitive laminie. 



its posterior extremity. Between the bars and the wall are enclosed the 

 extremities of the sole, which are often injured by a badly-fitted shoe, 

 especially upon the inner side, 

 and the resulting bruise is called 

 a " corn ". The bars assist in 

 preserving the width of the foot 

 at the heels, and when cut away 

 l:)y the farrier, permit contrac- 

 tion of the hoof. 



Bars, sole, frog, and wall 

 form one continuous horny 

 covering to the foot. By long 

 maceration in water they can 

 be sejDarated, but in a healthj 

 living foot they are all firmly 

 united so as to form a sound 

 hoof Each division should be 

 kept in its most perfect condi- 

 tion, because any long-continued 



defect of one is certain to afiect the other injuriously. If the wall at 

 the heels be left too high, the frog soon shrinks and wastes. If the 

 sole be cut away and weakened, the wall 

 has to support unaided an excess of weight, 

 and it becomes broken and diseased. Wall, 

 sole, and frog must be kept proportionate if 

 the proper relations of the whole hoof are 

 to l)e maintained. 



Internal Structure of Hoof. — Al- 

 though the hoof is a firm, strong, protect- 

 ing covering to the sensitive foot witliin 

 it, very serious injury to the horse results 

 from defects in its structure which are often 

 overlooked. These will be appreciated more 

 readily when it is known that within the 

 hoof is a particularly delicate and complex 

 arrangement. When a hoof is removed with 

 care, a beautiful, sensitive structure is ex- 

 posed, having a contour exactly matching 

 the inner surface of the hoof (figs. 626, 627). 

 The inner surface of the wall is covered with rows of thin, horny plates 

 running from above downwards parallel to each other, all sloping forwards 



Fig. 627.— The Sensitive Foot : Sole 

 and Frog 



A, Median cleft of fleshy frog. B, La- 

 minjB of the bars. C, Velvety tissue of 

 the frog. D, Velvety tissue of the sole. 



