THE SKIN 



229 



The skin is quite elastic and is really somewhat larger than 

 is necessary to cover the body. If it be seized by the fingers 

 almost anywhere, e.g. on the back of the hand, it can easily 

 be lifted into a fold, but returns to its original place when 



hfyidcr/n/s 



Blood 

 Vessels 



Dermis 



Flattened 

 Cells ^ 



Sense * 

 Body 



Growing 

 Ce///- 

 E>lood 

 tessek 



Nerves 



FIG. 112. SECTION THROUGH THE SKIN 



Showing the layers of the epidermis and the sense organs and blood vessels of the 



dermal papillae. 



released. On account of this elasticity it readily accommo- 

 dates itself to the shape of the body, and is ordinarily stretched 

 smoothly over it. As a person grows older, it becomes less 

 elastic and is finally thrown into wrinkles. 



THE EPIDERMIS 



The inner surface of the epidermis is composed of a layer 

 of growing cells, somewhat rounded in shape; Fig. 112. 

 They are nourished by the blood from below, and are con- 

 stantly multiplying and growing. As they increase in num- 

 bers the new cells push the older ones toward the outer sur- 

 face of the skin, and the epidermis is thus made thicker by 

 growth in its deeper layers. As soon as the cells are pushed 

 away from the deep, growing layer, they cease to have life 



