4-28 HYBEUNATION OF INSECTS. 



the eggs of these particular species, is abundantly ob- 

 vious. Insects whose eggs are to be hatched in summer, 

 usually fix them slightly to the leaves upon which the 

 larvae are to feed. But it is evident that, were this plan 

 to be adopted by those whose eggs remain through the 

 winter, their progeny might be blown away along with 

 the leaf to which they are attached, far from their de- 

 stined food. These, therefore, choose a more stable sup- 

 port, and carefully fasten them, as has just been observ- 

 ed, either to the trunk or branches of the tree, whose 

 young leaves in spring are to be the food of the excluded 

 larvae. The latter plan is followed by the female of 

 Trichoda Neustria, which curiously gums her eggs in 

 bracelets round the twigs of the hawthorn, &c. But an- 

 other provision is demanded. Were these eggs of the 

 usual delicate consistence, and to be attached with the 

 ordinary slight gluten, they would have a poor chance 

 of surviving the storms of rain and snow and hail to 

 which for six or eight months they are exposed. They 

 are therefore covered with a shell much more hard and 

 thick than common; packed as closely as possible to 

 each other ; and the interstices are filled up with a tena- 

 cious gum, which soon hardens the whole into a solid 

 mass almost capable of resisting a penknife. Thus se- 

 cured, they defy the elements and brave the blasts of 

 winter uninjured. The female of Hypogymna dispar, 

 whose eggs have a more tender shell, glues them in an 

 oval mass to the stem of a tree (whence the German 

 gardeners call the larvae Stamm-raupe\ and then covers 

 them with a warm non-conducting coat of hairs plucked 

 from her own body, equally impervious to cold and wet. 

 Another of those beautiful relations between objects at 



