OAK APPLE 135 



ful owner of the gall and live in its house. If it were not for 

 its enemies, galls might multiply and cover every oak leaf in 

 a forest. 



Other Kinds of Oak Galls. — On scrub oak and white oak 

 twigs you may often see white spongy masses that are called 

 vinegar balls, and are sometimes eaten for their sour taste. 

 They are made up of tufts of fibers that grow from ha-rd ker- 

 nels. In each kernel there lives a young insect. Keep some 

 of the vinegar balls in a jar to see the small black flies that 

 come from them. 



You may often find on oaks hard red galls, and also soft 

 red galls that look like drops of gum. Look for grubs inside 

 of them. What other kinds of oak galls do you find ? 



The galls on a kind of oak in Asia Minor are the gallnuts 

 that are used in making black dyes and ink. 



Swamp Apples. — On the twigs of swamp honeysuckles you 

 may often see greenish white lumps like small apples. They 

 look like galls, but are really a growth of something that is 

 like a mold. 



