118 HABITS AND INSTINCTS OF ANIMALS, CHAP. IV. 



maggots, one species of which is found in our richest 

 cheeses., and produces a little black fly (Tephritis 

 putris). These creatures appear to accomplish their 

 enormous leaps somewhat in the same manner as sal- 

 mon, by taking the tail in the mouth, and then sud- 

 denly letting it go again. Swammerdam assures us, 

 "that he beheld one, which was not more than the 

 fourth part of an inch in length, jump out of a box six 

 inches in depth ; which is as if a man, six feet high, 

 should raise himself in the air, by jumping, 144 feet!"* 

 The mode by which the caterpillar of the common 

 cabbage butterfly climbs is very singular. It may be 

 often seen ascending wells, or even the slippery glass 

 of our windows ; and, on careful examination, it will 

 be seen that they leave the mark of their track behind 

 them ; if this track be again examined through a mi- 

 croscope, it will be found to be nothing less than a rope 

 ladder, formed of silken threads, which the insect spins 

 in its progress. Other caterpillars resort to the same 

 contrivances for suspending themselves in the air; as 

 may be readily discovered by merely shaking the 

 branches of an oak or other tree, in summer, when 

 numbers of these little larvae will cast themselves down 

 by means of a hair-like thread, up which they can 

 again climb, so soon as all appearance of danger is at 

 an end. In their pupa state, nearly all the most typical 

 of the Ptilota, or four- winged insects, are quiescent ; 

 but those of the Hemiptera, Hymenoptera, and Neur- 

 optera, are as active as the larvae, and chiefly differ 

 from them in having the rudiments of wings. 



(139.) Perfect insects f, or those with four wings, 

 employ various methods of ascent. Some climb by means 

 of their claws ; others, by soft cushions, composed or 

 hairs, thickly set upon the under side of the claw joint; 



* Int. to Ent 



t As we have employed this term occasionally in our former volumes, 

 without, for particular reasons, denning its extent, we shall now inti- 

 mate, that in our entomological volumes we shall regard the Ptilota as 

 composed only of the following five orders, each being furnished with four 

 wings, namely, the Lepidoptera t Hemiptera>Mymenoptera> Coleoptera t 

 and Neuroptera. 



