132 



HOUSE-SHOEING. 



suddenly inflected or bent inward at the heels, toward the middle 

 of the sole, to form the "bars," which are merely prolongations of 

 its extremities; it constitutes the circumference or margin of the 

 hoof, is the part of the horny box that is intended more especially to 

 come into contact with the ground, and is that on which the iron de- 

 fense rests, and through which the farrier drives the nails that attach 

 it. The inner face of its upper edge is hollowed out into a somewhat 

 wide concavity, which receives, or rather in which rests, the coronary 

 cushion ; this concavity is chiefly remarkable for being pierced every- 



Fig. 4.— Profile of a Five-year-old Front Hoof that had never been 

 Shod ; external face.— Angle of wall at toe 51deg ; a a, frog baud or 

 periople ; b, wall ; c, toe, between wbich and cl is the " outside " or 

 "inside" toe or " mammilla," and between c and / the "outside" or 

 "inside" heel. 



where by countless minute openings which penetrate the substance of 

 the wall to some depth ; each of these perforations receives one of the 

 " villi," or minute tufts of blood-vessels already mentioned as pro- 

 longed from the face of the membrane covering the interior of the 

 foot. Below this concavity, which receives a large share of the horse's 

 weight, the wall is of about equal thickness from top to bottom 5 on 

 the whole of its inner surface are ranged thin, narrow, vertical horny 

 plates, in number corresponding to the vascular laminae, between 

 which they are so intimately received or dovetailed — a horny leaf 

 between every two vascular ones — that in the living or fresh state 



