26 GENERAL ANATOMY. 



25. It exists to the greatest extent among the coloured races, 

 especially negroes, the entire surface of whose bodies is covered 

 with it. It here lies between the ctttis and rete Malp. of the 

 epidermis. It is not black, but dark brown, and thus gradually 

 proceeds even into yellowish. Among the Caucasian tribes it is 

 especially found in the eye on the posterior surface of the iris. 

 Moreover, also in the healthy state about the female nipple, on 

 the skin of the scrotum, of the great labia, and of the anus, in the 

 Bronchial glands ; in pathological conditions, as Freckles, and in 

 scirrhous growths. 



The pigment tissue consists of globular, multangular, or tubular, elongated 

 cells (pigment cells) in which the coloured particles lie (pigment corpuscles). 

 The pigment from the internal surface of the Choroid coat of the globe of the 

 eye is the best for examination. 



The cells are destroyed by putrefaction, and are soluble in acetic acid; 

 the pigment granules pass out, as extremely small, flat points, which, only 

 when they are heaped together, present a yellowish red and brownish ap- 

 pearance. They are only soluble in caustic Potash, and become changed in 

 colour by Chlorine. 



The ashes of the Pigment consist of muriate of soda, lirne, phosphate of 

 lime, arid oxide of iron. The purpose fulfilled by the Pigment in the skin 

 cannot be decided ; in the eye it serves to protect it from too strong light. 

 Pigment is wanting in the eyes as well as in the hair of Albinos. 



26. Hairs, Pili s. Crines, 



are thin, hard, elastic, and thread-like cylinders of various colours. 

 Non-vascular and without nerves like the foregoing tissues, they 

 must, however, on account of their more complicated structure, 

 be considered as more highly organised. They are also nourished 

 by a highly vascular basis, which is regarded as an inversion of 

 the cutis. 



The whole external surface of the body is covered with larger 

 or smaller hairs, with the exception of the palms of the hand, the 

 sole of the foot, the lips, the superior eyelid, the foreskin, Glans 

 penis, and Clitoris. 



Structure. The roots of the hair lie deeply in the cutis, sur- 

 rounded by the hair follicle, and seated with the soft club-shaped 

 bulb upon the germ of the hair (Pulpa). The body or shaft of 

 the hair projects beyond the surface of the body, and terminates 

 in a free point. 



In the shaft two substances are distinguished : 



a. The Cortex, is transparent and smooth, striated longitudinally, fibrous, 

 especially towards the roots. The transverse striae, which are observed upon 

 it. consist of encircling scales, which may be detached by the action of 

 Sulphuric Acid. 



b. The medullary substance is wanting at certain points in coarse, and 

 sometimes altogether in fine hair. It consists of small globules, resembling 

 fat drops, is dark, and never found in the point of the hair. Diameter 



