64 THE NAILS. 



arranged in rows. The epidermis fills up the hollows 

 between those of the same row, but dips down be- 

 tween neighboring rows. In this way the fine ridges 

 and furrows of the palm are produced. The deeper 

 grooves of the palm, from whose size and course gyp- 

 sies pretend to tell the fortune, have a different cause. 

 They mark lines where the skin is most frequently 

 folded in the movements of the hand, and where it is 

 more tightly tied down to the parts beneath it. 



10. Nails are made by a great development of the 

 horny layer of the epidermis on the ends of the toes and 

 fingers. This layer at these places becomes very thick, 

 and grows out beyond the rest of the skin to form the 

 edge of the nail. Our nails provide an armor to protect 

 the tips of the tender fingers and toes, which are liable 

 to many accidents. This protective use of the nail is 

 well seen in the hoof of a horse or cow, which is but a 

 thick nail. In beasts of prey, as cats and lions, the nails 

 take the form of claws and are used in climbing and in 

 catching prey. 



Each nail is nourished by thedermis beneath it, and at 

 its root. If it be torn off, or be shed in consequence of a 

 blow, it is reproduced, provided the dermis also has not 

 been seriously injured. 



11. Hairs, long or short, coarse or fine, scanty or nu- 

 merous, are found all over the skin except in a few 

 places, as the palms of the hands and the soles of the 



10. Of what are nails made ? Use of the nails to man ? What is a 

 hoof? A claw ? How are nails nourished? What is necessary in 

 order that a " cast" nail may be replaced ? 



11. On what parts of the skin are there no hairs ? What is a hair ? 

 What is the use of its papilla ? What is the follicle of a hair ? The 

 root ? What are the uses of hairs ? 



