THE HAIES. 71 



tactile corpuscles. Varicose nerve fibrils have been traced between 

 the cells in the rete mucosum of the epidermis. 



APPENDAGES OF THE SKIN. 



The appendages of the skin are the hairs, sebaceous glands, 

 sudoriferous glands, and the nails. 



THE HAIRS. 



A hair, consisting of a root and shaft, is constructed from elongate 

 cells which are cemented together, and overlapped with cell-plates. 

 The central part of medullated hairs is composed of cubical cells, pig- 

 ment, and occasional minute air bubbles. 



The root penetrates the stratum corneum and (appearing to have 

 pushed the rete mucosum before it) passes through the true skin and 

 terminates in a bulb usually in the subcutaneous tissue, where it 



Fia. 55. TRANSVERSE SECTION OF HAIR, AND HAIR-FOLLICLE. Partly Diagrammatic. 



A. Meiulla of hair. . 



B. Cortex of same. 



C. Root Sheath. 



D. Glassy membrane. 



E. Fibrous wall of the follicle, 



rests upon a papilla composed of an extremely delicate plexus of 

 blood capillaries. 



The Hair Follicle. The root of the hair, in its passage to the 

 papilla, is invested with sheaths derived from the skin. The hair, 

 with its follicle, is indicated in transverse section in Fig. 55. A 

 represents the medulla, and B the cortex of the hair. Outside the 

 root sheath C, and derived from the rete mucosum of the epidermis, 

 is a thin layer, the glassy membrane D. This is projected from the 

 basement membrane covering the surface of the corium or true skin. 



