466 



LETTER 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 thosa 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 movements they give to different parts of their body when in a state 

 of repose : and in order to /-ender 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 ; 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 traveling singly ; at other times in count- 

 less swarms: these the busy children of the day, and those of the night. 

 If you return to your apartment — there are these ubiquitaries — some fly- 

 ing about — others pacing against gravity up the walls or upon the ceil- 

 ing — others walking with ease upon the glass of your windows, and some 

 even venturing to take their station on your own sacred person, and assert- 

 ing 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 

 locomotive beings. In the variety of motions which they exhibit, we 

 see, as Cuvier remarks^, 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 pro- 

 vision made for these motions in the structure of their bodies is most won- 

 derful 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 incomparable provision made in the feet of such as walk or hang upon 

 smooth surfaces ; the great strength and spring in the legs of such as 



' Anatom. Compar. i. 444. 



