78 INTERNAL ANATOMY OF INSECTS. 



writer, who, upon putting a thermometer into a bee-hive 

 in winter, found it stand 27 higher than in the open air ; 

 in an anthill, he found it 6 or 7 higher ; in a vessel 

 containing many blister-beetles (Cantharis vesicatoria,) 

 4 or 5 higher. A thermometer, standing in the air at 

 14? R., put into a glass vessel with Acrida viridissima, 

 in nine minutes rose to17 c , and a similar result was ob- 

 served with respect to other insects a . Dr. Martine says 

 that caterpillars have but two degrees of heat above that 

 of the air they live in b . Coleopterous insects are said 

 to move slowly and with difficulty when the thermometer 

 sinks to 36, to become torpid at 34- , and to lose mus- 

 cular irritability at a lower degree c . I have before ob- 

 served that some insects will bear to be frozen into an 

 icicle, and yet survive d : they share this power with 

 reptiles, fishes, and amphibia. But, however small the 

 excess of it in some insects above that of the medium 

 they inhabit, it proves that they possess the power of gene- 

 rating heat. Whether, like the warm-blooded animals, 

 they generally possess that of resisting heat by perspira- 

 tion, &c. is not so clear. Yet the heat to which some 

 can bear to be exposed, basking at noon, as Dr. Clarke 

 informs us % on rocky and sandy places, exposed to the 

 full action of the sun, appears sufficient, if not resisted 

 by some principle of counteraction, to roast them to a 

 cinder. That bees perspire is well known, but probably 

 not singly. 



When the respiration of insects is suspended by im- 



a Inch, c. iv. Idecn zu Elner ZoocJiemie, 68 . 



b On Thermom. 141. c Carlisle in Philos. Trans. 180.5. 25. 



4 VOL. II. p. 229. e Travels ii. 482. 



