OF THE HUJMAN SKIN. 9 



means of getting rid of these animals, we hope 

 to be able to assist our readers in keeping a mens 

 Sana in corjpore sano, — a sound mind in a healthy 

 and cleanly body. 



The animal parasites of the human skin may be 

 divided into two classes ; those which live on the 

 skin, and those which live in the skin. We will 

 commence our study with those of the first class, 

 namely, the pediculi, of which there are three 

 kinds, — the head-louse, the crah-louse, and the 

 hody-louse. The first of these is met with only 

 on the hair of the head ; it is entirely confined to 

 the scalp, and never attacks the other hairy parts 

 of the body. It is unfortunately too familiar an 

 object to require any special delineation of it to 

 be given here. The color varies, livid or pale 

 gray, and is said to change according to the hair. 

 The male insects are fewer in number than the 

 females ; the latter are also much larger. They 

 have three pairs of legs, and all the feet are sim- 

 ilar. The last tarsal joint has a large claw on its 

 outside, and on its inside two straight, thick, 

 horny stumps, and a large bristle. A microscope 

 of moderate magnifying power will show this 

 structure of the animal. 



