431 



LETTEE XXII. 



MOTIONS OF INSECTS. {Larva and pupa.} 



AMONGST the means of defence to which 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 comprehensive survey of 

 them, including not only every species of locomotion, but also the move- 

 ments they give to different parts of their body when in a state of repose : 

 and in order to render this survey more complete, I shall add to it some 

 account of the various organs 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 every- 

 where in the air; dancing in the sun or in the shade ; creeping slowly, or 

 marching soberly, or running swiftly, or jumping upon the ground ; travers- 

 ing your path in all directions ; coursing over the surface of the waters, or 

 swimming at every depth beneath ; emerging from a subterranean habita- 

 tion, 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 other times in countless swarms : these the 

 busy children of the day, and those of the night. If you return to your 

 apartment there are these ubiquitaries some flying about others 

 pacing against gravity up the walls or upon the ceiling others walking 

 with ease upon the glass of your windows, and some even venturing to 

 take their station on your own sacred person, and asserting their right to 

 the lord of the creation. 



This universal movement and action of these restless little animals gives 

 life to every part and portion of our globe, rendering even the most arid 

 desert interesting. From their visitations every leaf and flower becomes 

 animated ; the very dust seems to quicken into life, and the stones, like 

 those thrown by Deucalion and Pyrrha, to be metamorphosed into loco- 

 motive beings. In the variety of motions which they exhibit, we see, as 

 Cuvier remarks 1 , those of every other description of animals. They walk, 

 run, and jump with the quadrupeds ; they fly with the birds ; they glide 

 with the serpents ; and they swim with the fish. And the provision made 

 for these motions in the structure of their bodies is most wonderful and 

 various. " If I was minded to expatiate," says the excellent Derham, " I 

 might take notice of the admirable mechanism in those that creep; the 

 curious oars in those amphibious insects that swim and walk ; the incom- 



1 Anatom. Compar. i. 444. 



