182 



APHANIPTEKA. 



which are called nits, to the hairs or feathers upon which 

 they climb. 



ORDER APHANIPTERA.* 



These insects, like those belonging to the pre- 

 ceding order, are wingless, but they undergo a meta- 

 morphosis. Their body is very much compressed at 

 the sides, and the legs adapted to leaping. The 

 mouth is provided with lancets, and performs the 

 functions of a sucking apparatus. In their larva 

 state they resemble little worms, and are quite 

 destitute of feet. The perfect insect lives upon 

 quadrupeds and birds. This order comprehends 



The Fleas (Pulex). The common flea (Pulex irritans) 

 lives upon dogs, cats, and men, whose blood it sucks. 

 The female lays about a dozen eggs, white and slightly 



FlG. 143. METAMORPHOSES OF THE FLEA. 



viscid. These eggs give birth to larvse, which are very 

 active. They roll themselves up into a spiral circular form, 

 and wriggle about like minute serpents. In about twelve 

 days these larvae enclose themselves in a little cocoon, 

 where they become nymphs, and in about twelve days more 

 issue forth in their perfect state. 



js, aplianes, hidden ; irrepoy, pteron, a wing. 



