INTRODUCTION. 
91 
are of this description, although these larvie are 
among the species which continue in company till 
they become pup®, 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 bo 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. 
Tliese larv®, as well as a large proportion of the 
species formerly alluded to, are converted into chr)’- 
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 of these wll be described here- 
after, in connexion with the particular history of 
the species which form them. They are usually 
