CH. XVI. 4 ] THE CATERPILLAR. 267 



They eat only the upper membrane of the leaf; 

 leaving- the larger nervures and the under skin un- 

 touched. The parts which they do not consume, 

 are wanted in order to construct a habitation to pro- 

 tect them against the inclemencies of the weather, 

 and conceal them from their natural enemies. As 

 soon as they have satisfied the calls of appetite, 

 some of the young caterpillars set about tying the 

 leaf, which, having been already rendered thin and 

 supple, is easily made to assume a concave shape. 

 The threads used in joining the edges of the leaf, so 

 as to give it a cup-like shape, are so many, that they 

 form a little silken roof, under which the caterpillars 

 feed. The exposure, however, to the light and 

 heat does not seem to be agreeable to them ; they 

 therefore add to the thin silken roof threads in such 

 quantities, that a perfectly white and impervious 

 web is made. These, after all, are but temporary 

 sheds hastily formed, until the insects have had 

 time to construct a more complete and durable fa- 

 bric. After the lapse of a few days they commence 

 the erection of their new abode, which is a silken 

 tent, sufficiently capacious to contain the whole 

 community, and so closely woven, as to afford them, 

 during the whole of the winter, a complete shelter 

 both from wind and rain. They lay the foundation 

 of their new edifice, by covering a shoot with silk, 

 and carefully nibbling away all the leaf-buds, so as 



