358 TYPES AND MARKET CLASSES OF LIVE STOCK 



is called laminous because it has the appearance of the leaves 

 of a book. There are 500 to 600 of these laminae which extend 

 from the top of the hoof to the sole. It is less thick than the 

 coronary layer, but, like it, is deflected forward at the heels 

 to help form the bars. 



Growth of the wall. At the lower end of the pastern, run- 

 ning along the edge of the hair from one heel around the toe 

 to the other heel, is a narrow ridge of pododerm, T^ to K of 

 an inch wide, called the perioplic ring. It consists of papillae, 

 which are microscopic nobs or nodules, and from each papilla 

 a shaft of horn grows downward, forming the periople of the 

 wall. Like the periople, the coronary layer grows downward 

 from a band of pododerm at the top of the hoof. This band is 



Fig. 116. The Parts of the Hoof. 



1, Wall; 2, sole; 3, branch of the 

 sole; 4, bar; 5, buttress; 6, frog; 7, 

 cleft of the frog; 8, bulbs of the heels. 



called the coronary cushion, and it lies just below and parallel 

 to the perioplic ring. At the heels it is deflected forward where 

 it produces the horn of the bars. The laminous horn is pro- 

 duced by that part of the pododerm known as the fleshy laminae; 

 these laminae extend up and down between the coronary cushion 

 and the sole. The fleshy laminae of the pododerm and the 

 laminous layer of the wall horn dovetail together, thus holding 

 the hoof securely to the foot. 



The sole horn is circular in shape except that it is notched 

 at the rear where it receives the bars and horny frog. It is 

 naturally concave below and is bounded at its edge by the wall 

 and bars. It is very brittle, non-elastic, and easily penetrated. 

 The sole horn is produced by the fleshy sole, which is that por- 

 tion of the pododerm covering the entire under surface of the 

 foot excepting the fleshy frog and bars. 



