DRAGON-FLIES, ETC. 219 



form of the wings in this species have, however, a 

 very marked difference in the two sexes, those of 

 the male forming at the hase a sharp angle towards 

 the hody, while those of the female arc rounded off 

 in the same part, and therefore quite free from the 

 angle in question. 



This, the most common of the Dragon-fly family, 

 has been made the subject of many curious experi- 

 ments : his wondrous eyes, with their endless num- 

 ber of convex facets, have been submitted to the 

 microscope of every curious naturalist, and his vo- 

 racity both in the larva and perfect state has been 

 tested by experiments which might seem very 

 cruel, but from our knowing that the sense of pain, 

 as we conceive it, is, from their peculiar structure, 

 almost absent in insects. Colonel Pringle decapi- 

 tated several Dragon-flies, among other experi- 

 ments, and a rather curious result followed, which 

 was that several of them lived for four months 

 without their heads, and one of the number for six 

 months, though with their heads on he could never 

 keep them alive beyond a few days. Mr. Haworth, 

 a well-known writer on British entomology, made 

 this Dragon-fly the means of proving to a 

 friend the fact, that insects have not a nervous 

 system, calculated for the transmission of a sense of 



