PRACTICAL MICROSCOPY. 



The whole is surrounded by a fibrous coat E, derived from the con- 

 nective tissue of the derma. 



A vertical section of the follicle is indicated in Fig. 56. A, B, and 

 C represent the epidermal layers which do not enter into its composi- 



FIG. 56. DIAGRAM SHOWING MODE OF FORMATION OF HAIR-FOLLICLE. 

 A'. Epidermal layers. 

 B'. Derma or true skin. 



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 the 

 root-sheath G. 



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

 glassy membrane, G. 



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



G. Root-sheath of the hair-follicle. 

 H. Glassy membrane of the follicle. 

 I. Fibrous sheath of the follicle. 



J. The hair-follicle. 



tion. The rete mucosum D forms the root-sheath at Gr. The base- 

 ment membrane of the corium E forms the glassy membrane H, 

 while the connective tissue' F constitutes the fibrous layer of the hair 

 follicle J. 



SUDORIFEROUS GLANDS. 



A sweat gland consists of a tube or duct (vide Fig. 57, at A) 

 which, from the opening upon the surface, passes in a spiral course 

 through the several layers of the skin to the deeper part of the 

 corium, where it becomes coiled in a bunch as at D. The coiled or 

 gland part of the tube is surrounded by a network of capillaries. At 

 B, the tube is seen in transverse section. The gland tube D is pro- 

 vided with a wall of connective tissue and smooth or involuntary 

 muscle, lined with conical cells. The epithelial lining of the duct C 

 is granular; the lumen small and lined with a thin cuticular mem- 



