HAIRS AND NAILS. 



417 



mainly to keep the skin and the hairs soft and pliable. Besides 

 this, it is probably excrementitious to a certain extent. 



Cerumen, commonly called " ear-wax," is the product of the 

 sebaceous and perspiratory glands of the external auditory meatus, 

 and is composed principally of fat with some soap. It is a 

 reddish substance having a sweetish-bitter taste. 



Hairs and Nails. These structures are modified epidermis. 

 The hair grows from the hair-papilla, in the interior of which 



FIG. 234. A normal sweat-gland, 

 highly magnified : a, sweat-coil, with 

 secreting epithelial cells; 6, sweat-duct; 

 c, lumen of duct; d, connective-tissue 

 capsule : e and /, arterial trunk and 

 capillaries supplying the gland (after 

 Neumann). 



FIG. 235. A normal sebaceous 

 gland in connection with a lanugo- 

 hair ; greatly magnified : a, con- 

 nective-tissue capsule ; 6, fatty 

 secretion ; c, h, fat-secreting cells ; 

 d, root of a lanugo-hair; e, hair-sac ; 

 /, hair shaft ; p, acini of sebaceous 

 gland (after Neumann). 



there is a blood-vessel. The integrity of this papilla is essential 

 to the existence of the hair ; when destroyed, the hair can never 

 be reproduced. It should be noted that the hair-papillae and the 

 papillae already described in connection with the corium are very 

 different structures, and should not be confounded. It has been 

 estimated that there are, on an average, 120,000 hairs in the scalp. 

 As a rule, the lighter the color of the hair the finer it is ; in the 

 female it is coarser than in the male. 



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