MOTIONS OF INSECTS. 3()7 



we consider the space that a fly will pass through in a 

 second, it is not wonderful that the eye should be unable 

 to trace its gradual progress, or that it should appear 

 present in the whole space at the same instant. The fly 

 we saw was a small male Ichneumon. 



Other circular motions of sportive insects take place 

 in the waters. Linne, in his Lapland tour, noticed a 

 black Tipula which ran over the water, and turned 

 round like a whirl wig, or Gyrinus"^. This last insect I 

 have often mentioned ; — it seems the merriest and most 

 agile of all the inhabitants of the waves. Wonderful is 

 the velocity with which they turn round and round, as it 

 were pursuing each other in incessant circles, some- 

 times moving in oblique, and indeed in every other 

 direction. Now and then they repose on the surface, 

 as if fatigued with their dances, and desirous of en- 

 joying the full effect of the sun-beam : if you approach 

 they are instantaneously in motion again. Attempt to 

 entrap them with your net, and they are under the water 

 and dispersed in a moment. When the danger ceases 

 they reappear, and resume their vagaries. . Covered 

 with lucid armour, when the sun shines they look like 

 little dancing masses of silver or brilliant pearls ^. 



But the motions of this kind to which I particularly 

 wish to call your attention, are the choral dances of males 

 in the air ; for the dancing sex amongst insects is the 

 masculine, the ladies generally keeping themselves quiet 

 at home. These dances occur at all seasons of the year, 

 both in winter and summer, though in the former season 



* Lack. Lapp. i. 194. 

 '' Compare Oliv. Entomol. iii. Gyrimis 4. 



