KEMEDIES. 177 



eggs in their bodies. The insects attacked 

 are not immediately killed by this operation, 

 which commonly takes place in the caterpillar 

 stage, but the caterpillars often live on and 

 pass into the chrysalis stage. By this time the 

 larvae of the insect which has attacked them 

 have hatched out and usually kill their host 

 by feeding on it in this stage, so that instead 

 of the expected moth or butterHy issuing from 

 the chrysalis, a number of flying insects, the 

 mature form of the attacking insect, make 

 their appearance. Not only caterpillars, but 

 all kinds of destructive insects may be thus 

 destroyed by other insects, and many species 

 that would otherwise become very injurious 

 are thus kept in check. 



PRACTICAL WOKK. 



I Collect a few caterpillars, together 

 with portions of the plant on which they are 

 feeding. Place these in a box in the bot- 

 tom of which is a little garden mould to the 

 depth of about l inches. Cover the box with 

 muslin, perforated zinc, or glass in such a man- 

 ner that the caterpillars cannot escape. Sup- 

 ply them with food, morning and evening. 



