AND THE LOWER ANIMALS. 57 



side of its body and extending over ten segments, a 

 series of little orifices, each, of which is surrounded 

 by a brown circle; these are the stigmata, or aper- 

 tures through which the air is admitted to the 

 respiratory organs, of which we shall say more fur- 

 ther on. 



The caterpillar of the cabbage butterfly completes its 

 growth about the month of October or November. It 

 now prepares for its first metamorphosis by ceasing 

 to eat, and thus completely emptying its digestive 

 tube ; then it seeks the hollow of some tree, or hole 

 in some neighbouring wall, and having found a suitable 

 spot, it begins its preparations. 



Unlike the silkworm, this caterpillar spins no cocoon 

 for its concealment and protection, but undergoes its 

 metamorphosis in the open air. It now commences 

 covering the spot it has chosen with filaments which 

 cross each other in every direction; and this silken 

 couch, delicate in texture, but withal of considerable 

 strength, serves as a solid and firm support for the 

 hinder limbs. Then bending its trunk and head pos- 

 teriorly almost to the middle of the back — like an 

 acrobat who makes a hoop of his body — it fixes a 

 thread first on one side and then upon the other, and 

 continues the operation till it has formed a kind of 

 girth, composed of about fifty filaments. This done, it 

 straightens its body, and undergoes its last moulting ; 

 the animal however which emerges from the cast-off 

 skin is no longer a caterpillar, but a chrysalis, which is 

 sustained horizontally by the hooklets of its tail and 

 the girth we have described, just like the reptiles and 

 fishes which are too large for the cases in our natural 

 history museums. 



