INTRODUCTION 45 



near the top. The caterpillars will be free to move all over 

 the open box but they cannot cross the band to escape. 

 Fresh leaves are easily placed in the open box and the 

 withered ones removed. 



The same plan may be adopted with wide glass jars, like 

 the ordinary battery jar. Choose a rather large one and 

 smear the inner side near the top with a band of sticky ma- 

 terial. The caterpillars are thus prevented from crawling 

 out, but they are open to observation at ^all times. {See 

 plate, pages 1^8-1^9.) 



In the case of the caterpillars that change to butterflies 

 no soil need be placed in the bottom of the jar as these will 

 attach their chrysahds to the sides or to a stick or board 

 which may easily be put in. In the case of many cater- 

 pillars that change to moths, however, it is desirable to 

 place about two inches of soil in the bottom of the jar. 

 Then if the caterpillars are not cocoon spinners they can 

 burrow into the soil when they are ready to change to 

 pupae. 



Instead of applying the sticky material directly to the 

 glass a strip of sticky fly paper may be glued to it. 



As a rule the buttei-fly caterpillar easiest to find lives 

 upon cabbages. Go into the garden and you are likely to 

 see a dozen green caterpillars upon as many cabbage 

 plants. Bring in several of the larger ones and place them 

 in a vivarium with some fresh cabbage leaves. In a few 

 days some of them will be likely to fasten themselves to 

 the vertical sides of the vivarium and shed the caterpillar 

 skin. Each thus becomes a chrysalis. About ten days 

 later this chrysalis skin will break open and a white 

 Cabbage butterfly will come out. 



So your caterpillar goes through the four different 



