LETTER XXiL 



MOTIONS OF INSECTS. (Larva and Pupa.) 



Amongst the means of defence to wliich insects have 

 recourse, I have noticed their motions. These shall be 

 the subject of the present letter. I shall not, however, 

 confine myself to those by which they seek to escape 

 from their enemies; but take a larger and more com- 

 prehensive survey of them, including not only every 

 species of locomotion, but also the movements they give 

 to different parts of their body when in a state of re- 

 pose : and in order to render this survey more com- 

 plete, I shall add to it some account of the various or- 

 gans and instruments by which they move. 



Whenever you go abroad in summer, wherever you 

 turn your eyes and attention, you will see insects in 

 motion. They are flying or sailing everywhere in the 

 air ; dancing in the sun or in the shade ; creeping 

 slowly, or marching soberly, or running swiftly, or 

 jumping upon the ground; traversing your path in all 

 directions ; coursing over the surface of the waters, or 

 swimming at every depth beneath ; emerging from a 

 subterranean habitation, or going into one ; climbing 

 up the trees, or descending from them ; glancing from 

 flower to flower; now alighting upon the earth and 

 waters, and now leaving them to follow the impulse of 

 their various instincts ; sometimes travelling singly; at 



