438 INSECTA. 



in several places, and the air-bladders in the abdomen, [which, besides] 

 answering the purposes of respiration, become necessary for flight. 



"When arrived at full maturity, they then work their way into life or 

 action a second time ; the chrysalis coat splits in several places ; first, 

 at the head, through which that part passes, and then along the body, 

 which soon follows, all the parts [in the pupse incompletse] being 

 drawn out of their sheaths. Those which have either made a nidus for 

 themselves, or have lined their cell, are obliged to work their way 

 through this; and with the silk- worm it is a pretty diifieult task. 

 Those which are under ground are obliged to work their way to the 

 surface, which, as in the case of the black-beetle, is sometimes eighteen 

 inches. They all, at the second birth, throw out the excrement which 

 has accumulated in the time of their chrysalis state : it is generally a 

 brown or yellow fluid, or rather a fluid mixed with a brown or yellow 

 substance. 



Of the complete Insect. — When the insect is completely formed and 

 emerges from the chrysalis state, its colours, whatever they may be, 

 are not so bright as they are some days after : thus the bee, wasp, <fec. 

 may be known to have just come from their cell. The external form 

 of the insect consists of three parts ; a head, chest, and abdomen ; the 

 head the smallest, the chest the next, and the belly the largest. The 

 legs come out from the lateral and lower parts of the chest ; the wings, 

 from the higher and lateral parts of the same. They have six legs, 

 three on each side. The two fore-legs 'are the shortest, the hind-legs 

 are the longest, and by much the strongest : they are obliged to be so, 

 as they arise so far forward, they must pass back to support the hind 

 parts of . the insect, especially when the insect walks horizontally ; for 

 the hind parts would, otherwise, fall to the ground while the head 

 would be raised ; acting upon the feet of the middle legs as a fulcrum. 

 The legs are in pairs ; and, in progressive motion, the right and left 

 move alternately. The motion of the three on each side is more com- 

 plicated, wherever we set out with the first motion. It is, if we begin 

 with the fore-foot, as follows : fore-foot, hind-foot, middle-foot : if we 

 begin with the hind-foot, it is then hind, middle, fore ; or, if we set 

 out with the middle-foot, it is middle, fore, and hind. "When they 

 move fast, they appear to lift up the fore-foot, before they set down the 

 hindmost one. 



Those insects which live through the winter are then inactive, in 

 countries where there are considerable changes in the seasons ; but in 

 countries where there is no great difference in the seasons, they con- 

 tinue longer in their annual actions. This state of inactivity arises 

 from cold, and has its different effects upon different insects. It may 



