GLANDS OF THE SKIN. 



331 



nail the Malpighian layer of the skin passes over into that 

 of the nail. The latter is covered over at this place of 

 transition by a horny layer, which extends along on the 

 lower surface of the free nail border, and is known as the 

 hyp o nychium. 



c? 



l&u 



.,.% 





Rid (left of 

 nail bed 



Cmnicctire 

 tixsm- of 

 nail bed 



Blood-vestd 



t 



Transverse section through the nail body. X 280. 



The growth of the nail proceeds, from behind, forward, by 

 a progressive transformation of the matrix cells into true nail 

 cells. This takes place at the posterior and lateral borders, 

 as well as the lower and often the upper surface of the nail 

 root. In consequence of this the nail is pushed forward, 

 while the Malpighian layer does not change its position. 



(<f) Glands of the Skin. 



Sebaceous Glands. 



The sebaceous glands, which are distributed over almost the 

 entire surface of the body, are found usually in connection with 

 hair follicles ; hence the name hair follicle glands. Only ex- 

 ceptionally do we find them in parts which are devoid of hairs 

 (e. g., the red borders of the lips, the labia minora, the glans 



