In the Stable, Field, and on the Road. 79 



crust is not liable to much variation in thickness, until 

 near the top, at the coronet, or where the horn of the 

 hoof unites with the skin of the pasterns ; here it 

 becomes abruptly thin, and appears as if scooped out ; 

 its colour and consistency also are changed, and it 

 appears like a continuance of the skin ; this thin portion 

 is called the coronary ring, which covers a thickened 

 prolongations of the skin called the coronary ligament. 

 This extension of the skin is supplied with numerous 

 densely-set blood-vessels, connected together by a fibrous 

 texture, many of which have the property of secreting 

 the horny substance which forms the crust. The crust 

 is composed of numerous fibres which proceed direct 

 from the coronary to the ground, but which follow an 

 oblique course from the heel forward ; the fibres are 

 held together by a glutinous substance, which, as before 

 mentioned, is secreted in the numerous blood-vessels. 

 The internal parts of the foot are composed of the 

 laminae, the sensitive frog, the navicular bone, and the 

 coffin bone. The lamina3 consist of numerous small 

 horny plates, which line the crust, resembling the 

 beautiful gills or underpart of a mushroom ; these 

 are arranged with the nicest order and mathematical 

 precision upon the internal surface of the wall ; they 

 extend in uniform parallels, in a perpendicular direction, 

 from the top of the hoof at the coronary to the line of 

 j unction of the wall with the sole, and are so thickly set 

 that no part of the superfices remains unoccupied by 

 them. They are also continued upon the surface of the 

 bars, and are soft, yielding, and elastic ; but from exposure 

 become dry and rigid. Every plate exhibits two edges 



