14 



STORIES OF INSECT LIFE. 



Before moulting begins the little cabbage worm rests from 

 eating. Then its skin splits open along the back, especially 

 toward the front end of the body, and the worm crawls out, 

 clothed in a new skin which has been formed beneath the old 

 one. It soon begins to eat the cabbage leaf again. 



The caterpillar is larger after this moult than before. It 

 feeds quietly for another week, and then it 

 sheds its skin again, being considerably larger 

 after the second moult. Thus the processes of 

 eating and moulting are continued for perhaps 

 two weeks longer. Then the cabbage worm 

 becomes full-grown, as far as this caterpillar or 

 larva stage of its life is concerned (Fig. 15, a). 

 The larva is now ready to enter upon the 

 next stage of its existence — that of the pupa 

 or chrysalis. The caterpillar seeks the side of 

 its cage, or if out-of-doors it finds some secure 

 shelter, and spins a silken loop to hold up the 

 front part of its body. It also spins a tuft of 

 silk in which to entangle its hind legs. Meanwhile its body 

 becomes short and thick. Then along the back a erack appears, 

 and the pupa wriggles out of the larva skin. The latter falls 

 off, leaving only the chrysalis attached to the tuft of silken 

 threads at one end, and held by the loop at the other end 

 (Fig. 15, h). 



The insect remains in this chrysalis state about two weeks. 

 Then the skin of the chrysalis splits open and a white butter- 

 fly comes out of it. At first its wings are small and cramped, 

 but they soon spread out and the butterfly takes wing, if given 

 its liberty. 



This butterfly is much like the one which laid the eg^ at 

 the beginning. It has thus gone thi-ough the four great stages 



Fig. 15. — a. Cab- 

 bage Worm ; b, 

 Chrysalis. 



