2 HISTORY OF 



they are not likely to meet disturbances. Some 

 mix sand with their gummy and moist webs, and 

 thus make themselves a secure incrustation ; 

 while others, before their change, bury them- 

 selves in the ground, and thus avoid the nume- 

 rous dangers that might attend them. One 

 would imagine that they were conscious of the 

 precise time of their continuance in their aurelia 

 state, since their little sepulchres, with respect 

 to the solidity of the building, are proportioned 

 to such duration. Those that are to lie in that 

 state of existence but a few days, make choice of 

 some tender leaf, which they render still more 

 pliant by diffusing a kind of glue upon it ; the 

 leaf thus gradually curls up, and withering as it 

 enfolds, the insect wraps itself within, as in a 

 mantle, till the genial warmth of the sun enables 

 it to struggle for new life, and burst from its con- 

 finement. Others, whose time of transformation 

 is also near at hand, fasten their tails to a tree, 

 or to the first worm-hole they meet in a beam, 

 and wait in that defenceless situation. Such ca- 

 terpillars, on the other hand, as are seen to lie 

 several months in their aurelia state, act with 

 much greater circumspection. Most of them 

 mix their web with sand, and thus make them- 

 selves a strong covering ; others build in wood, 

 which serves them in the nature of a coffin. 

 Such as have made the leaves of willows their 

 favourite food, break the tender twigs of them 

 first into small pieces, then pound them as it 

 were to powder ; and, by means of their gluti- 

 nous silk, make a kind of paste, in which they 



