LEPIDOPTEEA. 



233 



as thin and as clean as possible, and go to sleep in a good state of 

 health. When the mass of worms is well awake again, the next 

 thing to do is to take them off the litter on which they moulted 

 and to give them food. If this problem were proposed to a 

 person strange to the operation which is now occupying our 

 attention to separate the worms from the faded and withered 

 food upon which they are reposing, without touching them, he 

 would certainly be very much at a loss what to answer. 

 The solution of this problem presented for a long time great 

 difficulties, and occasioned numerous reverses in the rear- 

 ing. Now-a-days, thanks to the employment of a net, the 

 delitement, or taking them off their bed, has become an easy 

 operation. 



Over the worms, which cover a table, is spread a net, the meshes 

 of which are broad enough to allow them to pass through On 

 this net are spread the leaves which are to compose a meal. 



Fig. 211. Lozenge-shaped net. 



Fig. 212. Square net. 



The worms immediately leave the old food, and get on to the 

 new leaves. They then lift the litter with the worms, and 

 throw away the old leaves, now unoccupied, clean the table, and 

 replace the net with the worms. At the next delitement the first 

 net is found under the litter. Figs. 211 and 212 represent two 

 forms of these nets made of thread. 



Thread nets, which were of great use, have been supplanted 

 lately, with great advantage, by paper ones, which were invented 



