THE SKIN. 



time, and before the day's work is done his finger-ends are 

 worn tender. The rough bricks wear away the epidermis 

 faster than the new supply from the true skin is formed. 



The skin in those parts of the body most in use, as the 

 palm of the hand and sole of the 

 foot, is thick and hard. In the 

 hand of the laborer the palm be- 

 comes horny. In the barefooted 

 boy the sole of the foot grows thick 

 and tough. In ill-fitting boots parts 

 of the foot are so pressed upon and 

 rubbed that corns and bunions are 

 formed. 



In the deeper portions of the 

 epidermis are minute cells con- 

 taining coloring matter, called pig- 

 ment cells. This coloring matter 

 in the white race is of a pinkish 

 hue; in the negro it is brown or 

 black. The varying shades from 

 white to black are owing as much 

 to the thickness of this layer of 

 coloring matter, as to the coloring 

 matter itself. The sun's rays affect 

 these pigment cells, making the FlG . ig.-section of skin: a, 



skin darker. The tanned skin in superficial layer and, &, deep layer 



summer is much darker than the 



of the epidermis; c, papillae; d, 

 oil gland ; e, sweat gland ; /, spiral 



skin of unexposed parts. The in- termination of sweat duct; g, hair 

 , , ._, ,, ,, bulb; h, hair shaft; i, muscle 



habitants of the sunny south are which erects the hair. 

 darker than those of more northern 



regions. Sometimes the action of the sun affects the coloring 

 matter in spots, and freckles are the result. 



3. The True Skin. Beneath the epidermis is the cutis, 

 or true skin. It is formed of fine elastic tissue. This tissue 

 4 



