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its next condition, and gnaws in the leaf a round 

 opening, taking care not to cut through the 

 exterior thin layer of tissue, or epidermis. This 

 door is to serve the insect for its exit in due time. 

 But in proportion to its bulk, its green chamber is 

 of considerable size. How, then, shall the insect 

 know the exact place where its portal is situated ? 

 How, without a clue, shall it discover in its dark 

 abode the precise circle which requires only a 

 push to throw open its gate ? Even this is fore- 

 seen and provided for. Out of all other posi- 

 tions in which the little hammock, of which we 

 spoke, might have been hung, and they are 

 numerous, the larva has been directed so to place 

 it, that the silken cord which suspends the head is 

 fastened close to the side of the door which it has 

 previously constructed; and the insect, when it 

 emerges from the pupa, guided by this thread, 

 like Theseus, makes its way out of an apart- 

 ment which, but for this contrivance, might have 

 been to it a labyrinth as inextricable as that 

 of Minos. Other insects adopt the same pre- 

 caution of gnawing a doorway for the escape of 

 the perfect insect, only leaving a sufficient thick- 

 ness of outside tissue to protect the helpless 



