188 



MEANS OF DEFENCE OF INSECTS. 



in great numbers, and spreading over an acre of the top of a 

 gentle hill. In the midst of these boiling springs, within 

 three feet of five or six of them, rises a tepid one about blood 

 warm. But the most extraordinary circumstance which he 

 relates is, that not only confervas were found in the boiling 

 springs, but numbers of small black beetles, that died upon 

 being taken out and plunged into cold water. 1 — And once, 

 having taken in the hot dung of my cucumber-bed a small 

 beetle (Synchita Juglandis), I immersed it in boiling water; 

 and after keeping it submerged a sufficient time, as I thought, 

 to destroy it, upon taking it out, and laying it to dry, it soon 

 began to move and walk. Its native station being of so high 

 a temperature, Providence has fitted it for it, by giving it 

 extraordinary powers of sustaining heat. Other insects are 

 as remarkable for bearing any degree of cold. Some gnats 

 that De Geer observed, survived after the water in which 

 they were was frozen into a mass of ice : and Reaumur relates 

 many similar instances. 2 



The last passive means of defence that I mentioned, was 

 the multiplication of insects. Some species, the Aphides for 

 instance, and the Grasshoppers and Locusts, have such an 

 infinite host of enemies, that were it not for their numbers 

 the race would soon be annihilated. — But as passive means 

 of defence have detained us sufficiently long, it is enough to 

 have touched upon this head. Let us then now proceed to 

 such as may be called active ; in which the volition of the 

 animal bears some part. 



II. The active means of defence, which tend to secure 

 insects from injury or attack, are much more numerous and 

 diversified than the passive ; and also more interesting, since 

 they depend, more or less, upon the efforts and industry of 

 these creatures themselves. When urged by danger, they 

 endeavour to repel it, either by having recourse to certain 

 attitudes or motions ; producing particular noises ; emitting 

 disagreeable scents or fluids ; employing their limbs, or 



1 J.Mason Good's Anniversary Oration, delivered March 8, 1808, before the 

 Medical Society of London, p. 31. 



2 De Geer, vi. 355.; comp. 320., and Reaum. ii. 141 — 147. 



