OF PAPILIONACEOUS INSECTS. 57 



a state of hybernation till the succeeding spring. 

 That this condition and difference are attributable 

 to the influence of temperature, has been proved by 

 numerous experiments. These late laid eggs may be 

 hatched by placing them in the temperature of summer 

 heat. The Silk-worm is never hatched till six weeks 

 after its extrusion. However, by artificial means, the 

 ordinary laws of nature may be altered ; for in coun- 

 tries where they are much propagated on account of 

 the silk, it is the practice for women to hatch them 

 in less than a month, by carrying the eggs in their 

 bosoms. 



Kirby and Spence assert, that "to retard their 

 hatching with particular views is in any circumstances 

 impossible. When the heat of the atmosphere has 

 reached a certain point, the hatching cannot be 

 retarded by cellars; and M. Faujas has remarked, 

 that in time the Silk-worm's eggs would hatch in an 

 ice-house." * 



Contrary to the above assertion, in one instance, 

 and indeed the only time I ever tried the experiment, 

 I found that, by placing the eggs of a Silk-worm 

 Moth in a cold damp cellar, they were kept from 

 hatching from the year 1818 till the year 1820, 

 when they were exposed to the sun's heat, which 

 speedily brought them to the larva state. Young, 

 in his History of France, states, that no art will 

 hatch the eggs of the common Silk-worms the 

 first year, or that in which they are laid ; but that 



* Introduction to Entomology, iii. p. 102 



