430 HYBERNATION OF INSECTS. 



those of the former shall be hatched, simultaneously with 

 the expansion of the leaves, nearly a month earlier than 

 those of the latter : thus demonstrably proving that the 

 hybernation of these eggs is not accidental, but has been 

 specially ordained by the Author of nature, who has 

 conferred on those of each species a peculiar and appro- 

 priate organization. 



A much greater number of insects pass the winter in 

 the pupa than in the egg state ; probably nine-tenths of 

 the extensive order Lepidoptera, many in Hymenoptera, 

 and several in other orders. In placing these pupae in 

 security from the too great cold of winter and the 

 attacks of enemies, the larvae from which they are to be 

 metamorphosed exhibit an anxiety and ingenuity evi- 

 dently imparted to them for this express design. A few 

 are suspended without any covering, though usually in 

 a sheltered situation. But by far the larger number are 

 concealed under leaves, in the crevices or in the trunk 

 of trees, &c., or inclosed in cocoons of silk or other ma- 

 terials which will be described to you in a subsequent 

 letter, and often buried deep mider ground out of the 

 reach of frost. — One reason why so many lepidopterous 

 insects pass the winter as pupa?, has been plausibly as- 

 signed by Rbsel, in remarking that this is the case with 

 all the numerous species which feed on annual plants. 

 As these have no local habitation, dying one year and 

 spring'mg up from seed in another quarter the next, it is 

 obvious that eggs deposited upon them in autumn would 

 have no chance of escaping destruction ; and that even 

 if the larvoc were to be hatched before winter, and to 

 hybernate in that state, they would have no certainty of 

 being in the neighbourhood of their appropriate food 



