458 IIYIJEriNATlON OF INSECTS. 



del Fuego, as well uk Iroio otlier facU, is fc;t by mt\n 

 when exposed to a very low temper.iture ; yielding to 

 which, torpidity ensues. Others, admitting that cold is 

 the cause of torpidity, maintain that the sensations which 

 precede it are of a painful nature; and that the re- 

 treats in which Iiybernating animals pass the winter 

 are selected in consequence of their endeavours to 

 escape from the disagreeable influence of cold. 



I have before had occasion to remark'' the inconclu- 

 siveness of many of the physiological speculations of 

 very eminent philosophers, arising from their ignorance 

 of Entomology, which observation forcibly applies in 

 the present instance. The reasoners upon torpidity 

 have almost all confined their view to the hybernating 

 quadrupeds, as the marmot, dormouse, &c., and have 

 thus lost sight of the far more extensive series of facts 

 supplied by hybernating insects, which would often at 

 once have set aside their most confidently-asserted hy- 

 potheses. If those who adopt the former of the opi- 

 nions above alluded to, had been aware that numerous 

 insects retire to their hyberi)acula (as has been before 

 observed) on some of tiic finest days at the close of 

 autuum, they could never have contended that this 

 movement, in which insects display extraordinary ac- 

 tivity, is caused by the agreeable drowsiness consequent 

 on severe cold ; and the very same fact is equally con- 

 clusive against the theory, that it is to escape the pain 

 arising from a low temperature that insects bury them- 

 selves in their winter quarters. 



In fact, the great source of the confused and unsatis- 

 factory reasoning which has obtained on this subject, 

 ' Vol. 1. 2d £d. 33. 



