196 



PHYSIOLOGY AND HEALTH. 

 FIG. XXVin. Hair highly magnified. 



a, Artery. 



5, 5, Tubular part. 



c, Pulpy part. 



d, Pulpy bulb. 



e, e, Cuticle. 

 /, True Skin. 



the form of the scales is scarcely visible, except on the head. 

 This scurfy dust is constantly gathering upon the surface, 

 and needs to be frequently washed off with soap and water. 

 And when, after a long neglect of this duty, we rub the skin 

 vigorously in a warm bath, we feel this matter gather in little 

 rolls under the hand. After some fevers, this skin comes off 

 in little flakes, like scales of bran, but not in health, except on 

 the head. The loss of these outer layers is continually sup- 

 plied by the new growth of layers underneath from the inner 

 skin. This process of change gives the scarf-skin a constant 

 freshness of substance. 



4f>2. The cuticle is composed of several layers of thin 

 scales. The outer and the oldest are transparent. The pig- 

 ment cells, which are the seat of color, are situated in the 

 innermost ^nd the last-formed layer ofthe cuticle. The con- 

 tents of these cells give the different shades to the various 

 races of mankind, and to various individuals. This matter is 

 white or flesh-colored in the European and North American, 

 black in the African, yellow in the Mongolian, and copper- 

 colored in the American Indian. It is this which is dark- 

 ened or tanned by exposure to the sun, and bleached by pro- 



