FOES AND FRIENDS OF THE PLANT 



187 



see that they stop feeding; some of them may spin 

 soft silken cocoons in which they stay for some time. 

 One day the cocoon or pupa case will open, and out 

 will come a butterfly or moth. Then you will know 

 to what plant that butterfly or moth is a foe, and you 

 will try to protect your plants against it in future. 



FIG. 99. Sphinx moth. 



If you keep the moths in a fruit jar, they may lay 

 eggs. When the eggs hatch out, you may give the young 

 caterpillars some fresh leaves and see what great quan- 

 tities of food they eat, and how fast they grow. When 

 they are full-grown they may spin cocoons out of which 

 they come as perfect moths. Many moths do not spin 

 cocoons, and none of the butterflies do. 



