56 THE BUTTERFLY VIVARIUM. 



progeny as soon as the eggs placed near the prey are 

 hatched ; and the Mason "Wasp "builds up the hodies 

 of Caterpillars in the structure in which its larvae 

 are to come forth, taking care to select such as are 

 just about to change, and which are consequently 

 unlikely to attempt escape, being in a semi-dor- 

 mant state, in which they remain as nice, fresh, live 

 food for the carnivorous young as soon as they are 

 hatched. The Spider Wasp pursues a similar 

 method in providing a feast of spiders for its ex- 

 pected young — -just stinging the victims sufficiently 

 to prevent any attempt to escape, but not to kill them. 

 One of the most beautiful examples of the 

 arrangement of the eggs, with a view to their pre- 

 servation, and to the convenience of the exit of the 

 future larvae in a fitting position to commence 

 their future existence, is, perhaps, that afforded 

 by the instinct of the Gnat. Reaumur closely 

 observed the female in the act of constructing her 

 fairy raft of eggs, which she effected by gluing 

 them together as they were laid, while they were 

 supported and put into the requisite form by means 

 of the long hind-legs, which, being crossed for the 

 purpose, afforded the moulding shape for the pointed 

 end of the little boat ; for in that form the structure 

 is made. In this process, the top of the eggs is 



