20 INSECT MANUFACTURES. 



pillar that the case becomes detached from the 

 leaf, or naturalists have purposely severed a por- 

 tion to see what would be the result ; but this 

 does not greatly disturb the insect, for as long as 

 a single thread of silk remains to hold the pieces 

 together, the caterpillar is able to repair the evil. 

 It will unite the fractured portion almost imper- 

 ceptibly by means of silken threads, and proceed 

 with its case as before ; but if the leaf dry up and 

 wither, the insect is then compelled to desert it, 

 and to select a younger and fresher leaf for its 

 operations. 



What is still more curious, on the completion 

 of the dwelling, the caterpillar sometimes wishes 

 to make an excursion to another part of the leaf, 

 and to take its house with it, and this it accom- 

 plishes in the following manner. Coming more 

 than three parts out of the cone, the creature 

 makes new skeins in advance of the old, and 

 attempts to pull the cone forward by their means ; 

 but finding that this does not succeed, it bends its 

 body back, and quickly severs the old threads 

 and the portion of leaf which keeps the case 



