148 THE INSECT WORLD. 



the edges of the slit, and gradually pushes the old skin upwards. 

 Thus the caterpillar skin ascends, its plaits are pushed nearer and 

 nearer together, and it is soon reduced to a packet so small that it 

 covers only the end of the tail of the chrysalis (Fig. 106). 



But here comes the culminating point, the most difficult part of 

 the operation. The chrysalis, which is shorter than the caterpillar, 

 is at some distance from the silky network to which it must fix itself ; 

 it is only supported by that extremity of the caterpillar's skin which 

 had not been split open. It has neither legs nor arms, and yet it 

 must free itself from this remaining part of the skin, and reach the 

 threads to which it is to suspend itself 



The supple and contractile segments of the chrysalis serve for the 

 limbs which are wanting to it. Between two of these segments, as 



Fie. 106. — Chrysalis of the small Tortoise- 

 shell Butterfly completing the operation Fig. 107.— Chrysalis divested of the larva 

 of casting its larval skin. skin. 



with a pair of pincers, the insect seizes a portion of the folded skin, 

 and with such a firm hold that it is able to support the whole of its 

 body on it. It now curves its hinder parts slightly, and draws its tail 

 entirely out of the sheath in which it was enclosed. It then reposes 

 for an instant only, for it has not yet finished the laborious operation 

 of its deliverance. It must free itself entirely from the dry skin 

 which surrounds the extremity of its body. 



The insect curves the part which is below its tail in such a 

 manner that that part can embrace and seize the packet to which it 

 holds on. It then gives to its body a violent shock, which makes it 

 spin round many times on its tail, and that with great rapidity. 

 During all these pirouettes the chrysalis acts against the skin ; the 

 hooks of its legs fray the threads, and break them or disentangle 



