186 OUR BODIES AND HOW WE LIVE 



portion, which are continually dropping off or being 

 removed by friction. 



When these flattened scales are pressed together, they 

 become flatter and flatter ; and thus the hard, horny skin 

 is made, which is seen in places where the wear and tear is 

 considerable, as in the palms of the hands and the soles 

 of the feet. The callous places on the hands of the black- 

 smith, the carpenter, or the washerwoman are familiar. 



252. What gives the Skin its Color. In the deeper parts 

 of the scarfskin are tiny specks of coloring matter, hid in 

 little cells. These give the skin its color. In the fairer 



races, these specks are of 

 a pinkish color ; in the dark 

 races, the. pigment cells 

 are brown or nearly black, 

 and more closely crowded 

 together. 



FIG. 114. A Layer of the Outer Skin The rays of the SUn 

 from the Palm of the Hand. serve tQ darken thege 



specks, as is seen in the 



parts of the body exposed to direct sunlight. We often 

 see on the persons of laboring and athletic people a sharp 

 line drawn between parts of the arm or neck exposed to 

 the sun's rays, and other parts generally covered with 

 clothing. Some persons, however, tan much more readily 

 than others. When the pigment changes in spots, we 

 call them freckles. 



Experiment 57. Take a very fine and perfectly clean needle 

 and run the point carefully beneath the thin outer layer of the skin 

 at the junction of the ringers with the palm of the hand. Note 

 that the point of the needle is not felt and that there is no flow 

 of blood. 



