546 .ESTHESIOLOGY. 



groove, in which is lodged the coronary substance or band. In 

 this groove are numerous minute orifices, in which are inserted 

 the secretory villi of the coronary band. The inferior border is 

 that part in contact with the ground, and to which the shoe is 

 fitted. In an unshod animal it is always in wear, and protrudes 

 beyond the rest, more especially round the outer quarter, and is 

 known as the spread. The inner surface of the inferior border 

 is united in a very intimate manner with the periphery of the 

 sole. The external layer of horn in the wall is distinctively 

 known as the crust, and is secreted by the coronary band ; the 

 rest being secreted by the sensitive laminae. 



Supposing the hoof to rest 

 dn a perfectly level plane, the 

 line joining the toe to the 

 middle of the coronary border 

 should make with the ground 

 an angle of about 50 degrees 

 in the fore, and perhaps a little 

 more in the hind feet. An 

 angle exceeding or falling short 

 FIG. 211. to any extent of this, would in- 



Detached hoof supero-iaterai view. , Crust, dicate defective conformation. 



or outer laj r er of the wall ; b, Horny laminae ; T , . , , 



c, Superior "border ; d, Cutigeral groove ; e, Inner *& thlS particular, hOWCVCr, it 



surface of sole;/, Inner surface of frog; /.Frog- j g neC eSSary to make allow- 

 stay. J 



ances for many circumstances, 



such as the breed and age of the animal, the condition of the 

 foot, &c., which may influence the angle. 



SOLE. 



The sole is a thick plate of horn, which helps to form the 

 inferior portion of the hoof. It is comprised between the inner 

 border of the inferior part of the wall and the inflections or bars, 

 and presents two surfaces and two borders. The inferior or 

 external surface forms a vault, which is more or less concave 

 in different animals. The superior or internal surface is 

 unevenly convex, and is studded with a number of small orifices, 

 which run obliquely forwards ; into these are inserted the vascular 

 papilla? of the sensitive sole. The external border or circum- 

 ference of the sole is convex, abuts upon, and is united through- 

 out its whole extent to the internal part of the inferior border of 



