22t> INSECTS. 



tract, and draw the skin up towards their head 5 

 and, by strong efforts, soon afterwards push it en- 

 tirely off. In their chrysalid state they remain for 

 some time, to all appearance, perfectly inanimate ; 

 but this is only in appearance, for, on being taken 

 into the hand, they will always be found to exhibit 

 signs of life. It is singular that, in the changes of 

 insects, the intestinal canal is frequently very dif- 

 ferent in the same individuals, as they pass through 

 their three states. In the larvae this is composed of 

 two principal tubes, the one inserted into the 

 other: the external tube is compact and fleshy, 

 and the internal one thin and transparent. The 

 latter is always thrown out of the body previously 

 to the transformation. 



As soon as the parts of the animal, within the 

 shell of the chrysalis, have acquired strength suffi- 

 cient to break the bonds that surround it, the little 

 creature exerts its powers, and appears to the world 

 in its perfect state. For a little while it continues hu- 

 mid and weak ; but, as the humidity evaporates, its 

 wings and shell become hardened, and it soon after- 

 wards commits itself in safety to its new element. 



From the metamorphosis of insects I shall pro- 

 ceed to the examination of some of their more 

 important members, as observed in the perfect 

 state of the animals. 



Some writers have conjectured that the antenna 

 or horns of insects were their organs of hearing; 

 for it is evident, from various experiments, that 

 insects are possessed of this sense in a degree as 



