INTRODUCTION. 91 



are of this description, although these larvae are 

 among the species which continue in company till 

 they become pupae, a circumstance which might be 

 supposed to render a secure protection more neces- 

 sary. Their nests appear like an assemblage of 

 irregular webs, very transparent, and almost resem- 

 bling those spun by certain spiders. These form a 

 kind of hammock on which the caterpillars repose, 

 not even leaving it when they feed, but merely 

 stretching their heads over the sides. They seem 

 to be very sensitive, and on the slightest touch draw 

 back or advance on their silken couch. This they 

 are observed to do nearly in a straight line, without 

 turning to the right or left ; and on careful exami- 

 nation, it is found that this is occasioned by each 

 being enclosed in a kind of long sheath of filigree 

 work, of so delicate a texture as to be invisible to the 

 naked eye. In the course of their lives each society 

 makes seven or eight of these nests, a new one 

 being requisite every time they shift their quarters 

 in search of food. 



These larvae, as well as a large proportion of the 

 species formerly alluded to, are converted into chry- 

 salides in the same abodes they occupied during 

 their reptile state ; but many provide for their 

 safety, while in that comparatively defenceless con- 

 dition, by constructing cells of great strength and 

 solidity. Most pf these will be described here- 

 after, in connexion with the particular history of 

 the species which form them. They are usually 



