OF THE SKIN. 145 



In the yellowish skin of a Malay head in the anatomical collec- 

 tion at Wiirzburg, I find the same nppearance as in a dark-colored 

 European scrotum. It follows, then, that the epidermis of the colored 

 races is, in no essential point, distinguishable from the colored regions 

 in the white man, and it even agrees in nearly all respects with that 

 of certain localities (the areola of the nipple, for instance). 



Pathological coloration of the epidermis (freckles, mothers' marks, 

 &c.), according to Simon, Krause, Bk'rensprung, and my own observa- 

 tions, is produced exactly as the more intensely colored spots in the 

 white man, and as the color of the negro's skin. Pigment deposits in 

 the corium and in the papillae, such as may be seen in cicatrices, after 

 chronic inflammation of the skin, and frequently as in ichthyosis and 

 many ncevi, associated with a colored epidermis, in which the pigment 

 is developed directly from the blood-corpuscles and their coloring mat- 

 ter, must be carefully distinguished from the foregoing.* Numerous 

 instances of partially or entirely white negroes and of black Europeans, 

 not as a consequence of change of climate, but as a congenital or sub- 

 sequently arising abnormal condition of the skin, have been noticed (see 

 Hildebrandt. Weber, II. fig. 526 ; Flourens, Compt. rendus XVII.) 

 But, for the future, it will have to be remembered, so far as the dark 

 coloration of Europeans is concerned, that it may also arise from a de- 

 position of the coloring matter of the bile. 



44. The thickness of the epidermis as a whole, varies exceedingly, de- 

 pending especially upon that of the horny layer. It measures : 



l-75th to l-50th of a line, upon the chin, the cheeks, and brow, in the 

 external auditory passages, and upon the eyelids: 



l-50th to l-25th of a line, upon the bridge of the nose, on the breast 

 and nipple of a female, on the back of the toes and fingers, upon the 

 neck and back, on the inner and outer side of the thigh, on the scro- 

 tum and the Idbia minor a : 



l-25th to l-16th of a line, on the edge of the eyelids, on the male chest 

 and nipple, the hairy scalp, the chin, penis, prepuce, and glans 

 penis : 



l-16th to l-10th of a line, on the red external parts of the lips, on the 

 back of the hand: 



1-1 Oth to l-7th of a line, on the flexor side of the fingers and toes : 



dense around the nucleus, which is itself but rarely recognizable, except by the aid of 

 reagents, and does not seem to contain any of these darker granules. DaC.J 



* [A colored epidermis may also be produced by a parasitic vegetable growth, as in the 

 disease called pityriasis versicolor, in which the yellowish color of the epidermis, is owing to 

 layers of filaments and spores deposited under the epidermic cells. DaC.] 



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