HYBERNATION OF INSECTS. 433 
these particular species, is abundantly obvious. Insects 
whose eges 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 adopt- 
ed 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 destined food. 
These, therefore, choose a more stable support, and care- 
fully fasten them, as has just been observed, 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 Bombyx Neustria, which 
curiously gums her eggs in bracelets round the twigs of 
the hawthorn, &c. But another 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 tenacious gum, which soon hardens the whole into 
a solid mass almost capable of resisting a penknife. ‘Thus 
secured, they defy the elements and brave the blasts of 
winter uninjured.—The female of Bombyx dispar, whose 
eggs bave a more tender shell, glues them in an oval 
mass to the stem of a tree (whence the German garden- 
ers 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 
first sight apparently unconnected, which at every step 
VOL. II. ZF 
