78 INTERNAL ANATOMY OF INSECTS. 
sima, in nine minutes rose to 17°, and a similar result 
was observed with respect to other insects*. Dr. Mar- 
tine says that caterpillars have but two degrees of heat 
above that of the air they live in®. Coleopterous insects 
are said to move slowly and with difficulty when the 
thermometer sinks to 36°, to become torpid at 34°, and 
to lose muscular irritability at a lower degree*. I have 
before observed that some insects will bear to be frozen 
into an icicle, and yet survive’: 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 resésting 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- 
mersion in any fluid, it is often resumed, even when it 
has been long and they are apparently dead, if they be 
brought into contact with the atmosphere. Reaumur 
found this to be the case with bees‘; and Swammerdam 
tells us that the maggot of the cheese-fly ( Tyrophaga Casei 
K.) lived six or seven days in rain-water’: he found it 
* Inch, c. iv. Jdeen zu Einer Zoochemie, 68—. 
> On Thermom. 141, © Carlisle in Philos. Trans. 1805. 25. 
d Vor. Tip. 231. * Travels ii, 482. 
£ Reaum, v. 540. ® Swamm. Bibl. Nat. ii. 65. a. 
