XXXII. OAK APPLE 



Material. — Oak leaf galls of the kind that are commonly called oak 

 apples. Look for them in June on the under side of the leaves on small 

 red oaks or black oaks. Last year's dried galls that may be found among 

 the fallen leaves may also be used. 



Observation. — How large is an oak apple ? What 

 is its color? What is its shape ? Is it heavy or light ? 

 What markings are on its surface ? Are there any 

 holes in it ? 



How thick is its outer shell ? What do you find 

 inside of the shell? What is at the center of the 

 shell ? What do you find inside of the inner kernel ? 

 Do you find signs of an insect anywhere in the gall ? 



Drawing and Composition. — Write a description of 

 an oak apple. Illustrate your work with a picture 

 of the outside of a gall, and another picture of the 

 inside of one that is cut in two through its center. 



SUPPLEMENTARY WORK 



GaUflies. — About the time that your summer vacatiou be- 

 gins oak apples will tui'n brown and dry. Collect some and 

 keep them in a jar covered with muslin. In a short time a 

 reddish fly may be expected from each gall. 



In spring the full-grown flies lay eggs in the opening leaves. 

 When an Qgg hatches, the leaf forms a gall around the young 

 grub. Does a gall harm a leaf that it is on ? Do you ever 



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