4.40 HYBERNATION OF INSECTS. 
hybernacula is very various. Some are content with in- 
sinuating themselves under any large stone, a collection 
of dead leaves, or the moss of the sheltered side of an 
old wall or bank. Others prefer for a retreat the lichen 
or ivy-covered interstices of the bark of old trees, the 
decayed bark itself, especially that near the roots, or 
bury themselves deep in the rotten trunk; and a very 
great number penetrate into the earth to the depth of 
several inches. The aquatic tribes, such as Dytzsci, 
Hydrophili, &c. burrow into the mud of their pools; 
but some of these are occasionally met with under stones, 
bark, &c. In every instance the selected dormitory is 
admirably adapted to the constitution, mode of life, and 
wants of the occupant. Those insects which can bear 
considerable cold without injury, are careless of pro- 
viding other than a slight covering; while the more 
tender species either enter the earth beyond the reach of 
frost, or prepare for themselves artificial cavities in sub- 
stances such as moss and rotten wood, which conduct 
heat with difficulty, and defend them from an injuriously 
low temperature. It does not appear that any perfect 
insect has the faculty of fabricating for itself a winter 
abode similar to those formed of silk, &c. by some larvee. 
Schmid, indeed, has mentioned finding Rhagiwm mordax 
and Inquisitor, F. in such abodes, constructed, as he | 
thought, of the inner bark of trees; but these, as Illiger 
has suggested, were more probably the deserted dwellings 
of lepidopterous larvae, of which the beetles in question 
had taken possession?.—Most insects place themselves 
in their hybernacula in the attitude which they ordinarily 
a Illic. Mag. i. 216. 
