MOTIONS OF INSECTS. 



245 



Others of the motions in question are merely those of parts. 

 Butterflies, when standing still in the sun, as you have doubt- 

 less often observed, 



** Their golden pinions ope and close ; " 



thus, it should seem, unless this motion be connected with 

 their respiration, alternately warming and cooling their 

 bodies. You have probably noticed a very common little 

 fly, of a shining black, with a black spot at the end of its 

 wings (Seioptera vibrans 1 ). It has received its trivial name 

 (vibrans) from the constant vibration which, when reposing, 

 it imparts to its wings. This motion, also, I have reason to 

 think, assists its respiration. Some insects when awake are 

 very active with their antennae, though their bodies are at 

 rest. I remember one evening attending for some time to 

 the proceedings of one of those caseworm-flies (Leptocerus), 

 that are remarkable, like certain moths, for their long antennae. 

 It was perched upon a blade of grass, and kept moving these 

 organs, which were twice as long as itself, in all directions, as 

 if by means of them it was exploring every thing that oc- 

 curred in its vicinity. Many Tipulae, and likewise some mites 

 (Acarus vibrans and Gamasus motatorius), distinguished by 

 long anterior legs, from this circumstance denominated pedes 

 motatorii by Linne, holding them up in the air impart to 

 them a vibratory motion, resembling that of the antennae of 

 some insects. 2 I scarcely need mention, what must often 

 have attracted your attention, the actions of flies when they 

 clean themselves ; how busily they rub and wipe their head 

 and thorax with their fore legs, and their wings and abdomen 

 with their hind ones. Perhaps you are not equally aware of 

 the use to which the rove-beetles (Staphylinus L.) put their 

 long abdomen. They turn it over their back not only to put 

 themselves in a threatening attitude, as I lately related, but 

 also to fold up their wings with it, and pack them under their 

 short elytra. 



With respect to the motions of insects in action, they may 



^ 1 Meigen considers this as an Ortalis; but its peculiar habit of constantly 

 vibrating its wings indicates a distinct genus ; especially as the habit is not con- 

 fined to a single species. 

 2 De Geer, vi. 335. 



n 3 



