48 



DISEASES OF THE HORSE'S FOOT 



as the Root Sheath. This is made up of an outer layer of 

 columnar cells {the outer root slieath) corresponding to the 

 Malpighian layer of the epidermis, and of an inner horny 

 layer, next to the hair, corresponding to the more super- 

 ficial layer of the epidermis, and known as the inner root 

 sheath. 



The hair grows from the bottom of the follicle by a 

 multiplication of the cells covering the papilla upon which 



Fig. 24. — Section of Skin with Hair Follicle and Hair. 



a, The hair follicle ; h, the hair root ; c, the medulla ; d, the hair cuticle ; 

 e, the outer root sheath ; /, tlie inner root sheath ; g, the papilla from 

 which the hair is growing ; h, a sebaceous gland ; /, a sudoriferous 

 gland. 



its root is moulded. When a hair is cast off a new one is 

 produced from the cells covering the papilla, or, in case of 

 the death or degeneration of the original papilla, the new 

 hair is produced from a second papilla formed in place of 

 the first at the bottom of the follicle. 



The Sebaceous Glands are small saccular glands with 

 their ducts opening into the mouths of the hair follicles. 

 They furnish a natural lubricant to the hairs and the 

 skin. 



