INSECTA. 101 



ilar filaments at the caudal extremity. It harbors in 

 damp places, and delights in articles made of sugar; 

 runs rapidly, shooting forward like a fish. Although 

 found in Europe, it is not a native, but has been carried 

 there from America. 



The Louse (pediculus capitis). This well known pest 

 is about a line in length, only half as broad ; the skin is 

 hard and parchment-like, and when roughly pressed 

 cracks with a noise. It has six feet ; in front is a prob- 

 oscis or sucker, with which it pierces the skin. It 

 infests the head of human beings and other warm-blooded 

 animals, and multiplies most rapidly. Within the space 

 of six days a louse will lay fifty eggs, which are called 

 nits ; in six more the young come forth, so that in eight 

 weeks one louse grandmother can number five thousand 

 descendants. If a louse, placed upon a human head, is 

 examined through a magnifying glass, it will be seen 

 first to search for a pore into which it insinuates its pro- 

 boscis, and the body being transparent, a stream of blood 

 is at once perceived to rush into the stomach. Lice 

 belong to temperate climates only ; it is said that they 

 are certain to vanish from any one, however lousy he 

 may be, as soon as the equator is passed. Those found 

 on the negroes a case which never occurs south of the 

 line are black, and smaller than those which infest the 

 white races. There are several other species found in 

 clothing, etc. ; some are very small, others as large as 

 an apple seed ; these abound in Mexico. A strong 

 decoction of parsley seed, it is said, secures an effectual 

 riddance of these disgusting vermin. 



The Flea (pulex irritans) is reddish-brown, and about 

 half a line in length ; the body is encased in a kind of 

 finely-wrought armor. It has a sharp trunk which it 



