198 METHODS IN TEACHING 



be solid or covered with wire screen. Fill the tray with 

 loose soil, slightly moist, and the cage is ready for use. 



As a beginning ask the pupils to bring in any caterpillars, 



noting on what plants they are feeding so that fresh food 



may be supplied every day. If there is any 



difficulty in finding caterpillars, direct the 



children to look for them on parsley, sweet anise, milkweed, 



tomato, cabbage, tobacco, and cheese weed. Secure some 



of the eggs, for it is desirable to have the pupils see the 



development of some of the species from the egg stage. 



When the caterpillars reach full development, they will 

 become restless and crawl about seeking a place in which 

 to make their transformation. Note whether a cocoon is 

 formed or the chrysalis is simply hung in position, and 

 how. Some of the caterpillars found in the early spring 

 and late summer will complete their changes into moths 

 or butterflies in a few weeks ; others, especially those taken 

 rather late in autumn, will remain in the chrysalis stage 

 until the next spring. 



The eggs of grasshoppers may be secured in autumn by 

 catching the females and allowing them to deposit their 

 eggs in the soil in the bottom of the cage. Early in the 

 spring sow barley or wheat in the soil to furnish food for 

 the young when hatched. Eggs of the katydid are sure to 

 be found on twigs. Place these in the cage for hatching. 

 The young will feed upon the leaves of black walnut. The 

 caterpillars of the sphynx moths, found upon the tomato, 

 tobacco, and grape, burrow into the soil when they have 

 finished feeding. 



Other insects profitable for study are the aphids, or plant 

 lice ; the lady bugs, which feed upon them ; the lace-winged 



