XXII INTRODUCTION-. 



luminous, attracts the male. What then are the 

 instruments by which food is assimilated in the 

 insect ? Cuvier supposes that it is taken up by the 

 pores of the body as water by a sponge, by imbi- 

 bition. 



The muscles of insects are disposed in bundles, 

 the fibres of which are not connected together by a 

 cellular membrane ; they are fixed to the hard 

 parts, which are to be moved by horny tendons. 

 The body of the insect being symmetrical, the 

 arrangement of muscles is simple. The segments 

 of the abdomen have similar muscles, and one side 

 corresponds to the other. 



The thorax contains the muscles which move 

 the head up or down ; those which move the wings 

 and the feet, and some others of which the uses 

 are only guessed at. The muscles of a species 

 of caterpillar, the cossus ligniperda^ have been 

 reckoned, by Lyonnet, to amount to four thousand 

 — this makes them nine times more than those of 

 man. The prodigious power of some of these 

 living atoms is scarcely imaginable. The flea, 

 called by the Arabians "the father of leapers," 

 and the locust, jump two hundred times their own 

 length.- Supposing the same relative force to be 

 infused into the body of a man six feet high, he 

 would be enabled to leap three times the height of 

 St. Paul's. Insects walk, run, leap, fly, glide, and 

 swim; thus combining all the movements of all 

 animated beings. 



All insects have a knotted nervous system. The 

 knot nearest the head is composed of two lobes, 



