96 



STUDENTS HISTOLOGY 



or true skin. The whole is surrounded by a fibrous coat, E, de 

 rived from the connective tissue of the derma. 



A vertical section of the follicle is indicated in Fig. 69. A, B, 

 and C represent the epidermal layers, which do not enter into its 



FIG. 69. DIAGRAM SHOWING MODE OF FORMATION OF HAIR-FOLLICLE 



A'. Epidermal layers. 

 B'. Derma, or true sftin. 



A. Horny layer of epidermis. 



B. Stratum lucidum. 



C. Stratum granulosum. 



The three last mentioned form no part of the follicle. 



D. Rete Malpighii. This will be seen projected into the depths of -the true skin to form 

 Ihe root-sheath, G. 



E. Hyaline membrane covering the derma. This is projected into the follicle, forming the 

 glassy membrane, H. 



F. Fibrous tissue of the derma, forming the fibrous sheath of the hair-follicle, I. 



G. Root-sheath of the hair-follicle. 

 H. Glassy membrane of the follicle. 

 I. Fibrous sheath of the follicle. 



J. The hair-follicle. 



composition. The rete mucosum, D, forms the root-sheath at G. 

 The basement membrane of the corium, E, forms the glassy mem- 

 brane, H, while the connective tissue, F, constitutes the fibrous 

 layer of the hair -follicle, J. The scales lining the hair-follicle 

 are imbricated, and are directed downwards, fitting over the 

 scales covering the surface of the hair, which are directed up- 

 wards, and also imbricated. 



MUSCLES OF THE HAIR -FOLLICLES 



Attached to the fibrous layer of each hair -follicle is a small 

 band of involuntary or smooth muscular fiber the arrector pili. 

 This passes obliquely toward the surface of the skin; and when 

 contraction takes place, the follicle and hair are elevated, producing 

 the phenomenon known as goose-flesh. 



