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 sheath) 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 
b 
c 
| ae eee we h 
: | oo 4 
: (WZ ) Me A) y)} 
fy \ (Oyj 
1 V @ Hl 
Fic. 24.—Srcrion oF Skin witH Harr FouiicLe AnD Harr. 
a, The hair follicle; b, the hair root; c, the medulla; d@, the hair cuticle ; 
e, the outer root sheath ; 7, the inner root sheath; g, the papilla from 
which the hair is growing; h, a sebaceous gland; 7%, 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. 
Tae Sepackous Guanps 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. 
