HYBERNATION OF INSECTS. . 435 



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 Dytisci, 

 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 larvae. 

 Schmid, indeed, has mentioned finding Rhagium mor- 

 dax and Inquisitor 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 3 . Most insects place themselves in 

 their hybernacula in the attitude which they ordinarily 

 assume when at rest ; but others choose a position pecu- 

 liar to their winter abode. So most of the ground- 

 a Illig. Mag. i. 216, 

 2 F 2 



