44 FIELD ZOOLOGY. 



of Other orders which express the new lines of division and 

 discovery. 



The simplest insects are wingless, have little differen- 

 tiation of body form, and no free metamorphosis. These 

 are the Thysanura. The fish moth is an example of the 

 order and probably the member most frequently seen — 

 a wingless, swift-moving little creature with six legs. It 

 is often found among musty piles of paper or among folds 

 of clothing laid away. The Isoptera, or termites, have a 

 growth instead of metamorphosis, and only the kings and 

 queens of the colonies are winged. These insects are 

 sometimes called white ants. The Corrodentia, or book 

 louse order, is represented by the pale-colored, flattish 

 little creatures that hustle out of sight when you open 

 an old book long unused and a little musty. Some of 

 the Corrodentia are winged and all have incomplete 

 metamorphosis. The Mallophaga include the sheep and 

 the goat lice, and the bird lice. They have biting mouth 

 parts and eat wool, hair, or feathers, while the true lice 

 feed upon blood which they suck from the victim's body. 

 The Euplexoptera, or earwigs, resemble some of the rove 

 beetles, but may be distinguished by the fact that they 

 have a pair of forceps-like appendages at the caudal 

 end of the body. They have four wings and reproduce 

 by incomplete metamorphosis. They do not creep into 

 people's ears,, as the old notion had it, but usually are 

 predaceous, feeding, according to Howard, upon dead 

 insects, snails, and small living insects. The Physopoda, 

 or thrips, are mostly flower pests, though some of them 

 eat other insects. Sometimes, close down to a head of 

 red clover, you may see some small black insects which 

 try to frighten you off by thrusting the end of the abdomen 

 energetically up into the air. And if you are looking 



