152 ARTICULATES: INSECTS. 



abound in neglected orchards and upon wild-cherry 

 trees. The eggs from which they hatch are placed in 

 a cluster on the smaller branches, and are covered with 

 a water-proof varnish. They hatch about the time the 

 leaves unfold. The little caterpillars immediately form 

 a small tent between the forks of the branches. As 

 they grow, they enlarge the tent, surrounding it with 

 new layers. They feed at stated times, and return to 

 their tents when they have finished eating. In crawl- 

 ing from one twig to another they spin a silken thread, 

 which serves to guide them on their way back. They 

 rest in their webs at noon and in stormy weather. 

 When full grown, which is about the middle of June, 

 they leave the trees, separate, wander about for a time, 

 and at length, in some sheltered place, spin their co- 

 coons, which are oval and loosely woven, and the meshes 

 are filled with a thin paste, which, on drying, becomes 

 a yellow powder. They remain chrysalides about fif- 

 teen days. 



GEOMETERS, OR SPAN-WORMS. 



The Geometers are moths whose caterpillars seem to 

 measure the surfaces over which they pass. They are 

 obliged to move in this way, because 

 they usually have only ten legs, six 

 true legs on the fore part of the 

 body, and four prop legs at the hind 

 Fig. 284. Geometer, extremity. Geometers live upon 

 trees, and let themselves down to 

 to the ground by a silken thread which they spin from 

 the mouth while descending. When not eating, many 

 of them stand on the hind legs, with the body extended, 

 and in this attitude may easily be mistaken for a twig. 



