HYBERNATION OF INSECTS. 427 



It is probable that some insects of almost every order 

 hybernate in the egg state : though that these must be 

 comparatively few in number, seems proved from two 

 considerations : first, That the majority of insects as- 

 sume the imago, and deposit their eggs in the summer 

 and early part of autumn, when the heat suffices to hatch 

 them in a short period : and secondly, That the eggs of 

 a very large proportion of insects require for their due 

 exclusion and the nutriment of the larvae springing from 

 them, conditions only to be fulfilled in summer, as all 

 those which are laid in young fruits and seeds; in the in- 

 terior and galls of leaves ; in insects that exist only in 

 summer, &c. &c. The insects which pass the winter in 

 the egg state are chiefly such as have several broods in 

 the course of the year, the females of the last of which 

 lay eggs that, requiring more heat for their development 

 than then exists, necessarily remain dormant until the 

 return of spring. 



The situation in which the female insect places her 

 eggs in order to their remaining there through the win- 

 ter, is always admirably adapted to the degree of cold 

 which they are capable of sustaining; and to the ensur- 

 ing a due supply of food for the nascent larvae. Thus, 

 with the former view, Acrida verrucivora and many other 

 insects whose eggs are of a tender consistence, deposit 

 them deep in the earth out of the reach of frost; and with 

 the latter, Trichoda Neustria, Lasiocampa castrensis, 

 Hypogymna dispar, and some other moths, departing 

 from the ordinary instinct of their congeners, which 

 teaches them to place their eggs upon the leaves of plants, 

 fix theirs to the stem and branches only. That this va- 

 riation of procedure has reference to the hybernation of 



