HAIRS. 



feet. A hair is a thread of epid 

 top of a papilla of the dermis 

 bottom of a tiny pit in the skin. 

 On the papilla, new epidermic 

 cells are produced as long as 

 the hair continues to grow. 

 When a hair is shed or pulled 

 out, a new one grows in its 

 place if the papilla has not 

 been injured. The part of 

 a hair which lies within its 

 pit or follicle, is known as its 

 root. 



In many of the lower animals, 

 hairs have an important use as 

 clothing. In man the hair of 

 the head may serve this pur- 

 pose to some extent; it also 

 aids in protecting the skull 

 from injury. The eyelashes 

 keep dust from falling into the 

 eye; and the fine hairs over 

 most of the surface drag on 

 their roots when pushed and 

 aid in the sense of touch. The 

 papillae on which the hairs 

 grow, are richly supplied with 

 nerves. 



12. The Glands of the Skin.- 

 the body have as their special 



ermis which grows on the 

 (/, Fig. 22) placed at the 



FIG. 22. The root of a hair, em- 

 bedded in the pit of the skin in 

 which it grew. , stem of the hair, 

 cut short; <?, , root of the hair; c, 

 swollen end of the root which fits 

 on the papilla of the dermis, *, 

 which nourishes the hair; k, , 

 openings of the ducts of oil-glands. 



-Certain hollow organs of 

 duty the preparation of 



12. What are glands? A secretion ? A duct? What glands pour 

 their secretion on the skin ? 



