THE &AXV 



1157 



the skin becomes wrinkled; when they are short and nearly at right angles to the 

 surface, the skin cannot wrinkle. 



Pigmentation of the Skin. As previously stated, in certain regions the skin of the 

 white race is brown because of pigmentation (areola?, nipples, around the anus, 



PAPILUE OF-~' 

 CORIUM 



SUDORIFEROUS /* 

 DUCTS'"- 



x RIDGES OP 





i .'*.. 1 V'VS) MVS^S*. ViF^VkAj^fcsT.ft . : 



FIG. 869. The furrows and ridges of true skin on the palmar surface of one of the fingers, the epidermis 



having been removed. (Toldt.) 



axilla?, scrotum, labia majora). This is due to pigment within the epithelial and 

 connective-tissue cells of the papillary layer of the corium, and in the basal cells 

 of the epidermis. There are few or none of these pigmented cells in the stratum 

 corneum of one of the Caucasian race. 



"In negroes and other colored races the deep pigmentation is due to a similar 

 distribution of the pigment granules in the entire epidermis; but even here the 



RETE 

 VENOSUM 



SUBPAPILLARY 

 NETWOR 



EPIDERMIS 



-PAPILLARY LAYER 



RETE 



VENOSUM 



LAYER -v 

 LAYER' 



SUBCUTANEOUS 

 TISSUE 



FIG 870. The distribution of the bloodvessels in the skin of the sole of the foot. (Spalteholz.) 



pigmentation decreases toward the surface, although the uppermost cells of the 

 stratum corneum always contain some pigment. The nuclei of the cells are always 

 free from coloring matter. The question as to the origin of the pigment is as yet 

 unsolved." 1 



1 A Text-book of Histology. By A. A. Bcihm and M. von Davidoff. Translated and edited by G. Carl Huhpr. 



