METAMORPHOSES OF INSECTS 



cosy silken nest or covering around them, known as 

 the cocoon ;* occasionally the silk is mingled with 

 particles of wood or earth. Some of the butterflies 

 simply suspend themselves vertically by their hinder- 

 most legs, head downwards, or they carry a silken 

 cable across their body to keep them from falling, 

 affixing the girdle to the under-surface of an object 

 such as a leaf or twig. Many insects hollow 

 out a cell or cavity in the ground and 

 line it with web of silken material. The 

 larva being duly prepared, after a short 

 repose its skin splits, and with infinite 

 shuffling and wriggling is thrown off, and 

 then the insect is known as a pupa. In 

 the true flies the outer skin of the full- 

 grown larva is not shed, the maggot 

 contracts, while the skin gradually hard- 

 ens, assuming the appearance of an oval 

 brownish shell or case, which serves the 

 same purpose as a cocoon and affords an 

 admirable protection to the insect which 

 changes to pupa inside. 



-pi ,1 *i_ i i j brassic(e) protect- 



The being that emerges in its bright ed by a hardened 



i . rr c 11 uniform case, se- 



new coat is very different from the larva, creted from the 



- , . - 111 pores of the insect. 



tor the muscles have already shortened 

 and enlarged in certain parts, so modifying the 

 simple worm-like form that the entire shape and 

 limbs of the future perfect creature are apparent, 

 and the wings, though they are very small and in 

 rudimentary condition, may be plainly traced. The 

 new pupa, should it be that of a butterfly (see Fig. 

 i), as of Sphinx, having got rid of its larval skin, 



