150 HUMAN HAIR 



We should look at it from another standpoint. 

 '"The part projecting from the skin" is the 

 shaft, or scapus ; the part passing obliquely into 

 the skin is the root, or radix pili ; and at the 

 end of the root is the bulb, bulbus pili, having a 

 hollow underneath filled with a tissue belonging 

 to the corium, and termed the papilla. The 

 root is surrounded by a modified portion of skin 

 termed the follicle, in the formation of which are 

 found both corium and epidermis. The epider- 

 mal portion forms the sheath or sheaths. From 

 two to five glands open into the follicle, termed 

 sebaceous glands. A few bundles of plain, 

 smooth, muscular fibre pass obliquely from the 

 side of the follicle to the under surface of the 

 corium. These constitute the erector muscle 

 of the hair musculus arrector pili. When 

 they contract towards the corium they pull on 

 the sheath and erect the hair.' * 



The cuticle is formed of tile-shaped hard 

 cells, the edges of which sometimes project 

 from the surface of the hair. If a hair be 



* Text-Book of Physiology. McKendrick. (J. Maclehose 

 & Sons.) 



