18 



METHODS OF INSECT LIFE. 



more, and appears as a j^upa or chrysalis ; also how 

 in many instances, and especially those of insects 

 which lie inactive and defenceless whilst in the chry- 

 salis shape, the grub spins a web cocoon, or hollows 

 out a cell in timber or in the ground, or in some way 

 avails itself of some kind of shelter for the coming 

 need of it. Here the change, which was beginning 

 when the larva took shelter, is gradually completed. 



The accompanying figures show the change that 

 takes place in the case of the Corn Ground Beetle, and 

 also in the Heart and Dart Cabbage and Turnip Moth. 

 The form of the creature, which was contained in the 



Fig. 10. — 1, Heart and Dart Moth ; 2, caterpillar ; 3 and 4, chrysalis 

 in earth-cell. 



caterpillar or grab or maggot-skin, alters ; the legs, 

 the wings, the mouth apparatus, and all the other 

 parts which the insect will possess in its perfect state, 

 develop, until within the old dead caterpillar-skin, or 

 with in the contracted skin of some kinds of Fly mag- 

 gots, there lies a distinctly differently shaped creature. 

 The change is gradual ; but the operation by which 

 the chrysalis casts off its useless coat, and appears in 

 its changed state, is often the work of a very few 

 minutes. This may easily be seen with some butterfly 

 caterpillars, and especially with the spiny black-and- 

 white-spotted caterpillars of the Peacock Butterfly, 

 which may often be found in large numbers on Nettles. 



