206 



NATURE-STUDY REVIEW [12:5— May, 191G 



being pointed and others variously sculptured and colored. (Fig- 

 ures 5, 6, 7, 8,). 



Twig and bud galls are generally globular in form or approxi- 

 mately so. They are sometimes singly placed, but very often 



occur in grapelike clusters. 

 The oak fig gall consists 

 of several individual galls 

 grouped in a tightly fit- 

 ting mass; the willow or 

 potato gall looks very much 

 like an old dried up speci- 

 men of the potato, and the 

 blackberry seed gall is easily 

 mistaken for a cluster of 

 woody seeds. 



Fig. 6. Wild Cherry Pouch Gall . 



Stem-like, expanding at the end into a pouch- 

 like sack. About two-fifths in. long. Hollow, 

 with an exit on under side of leaf. Green 

 orj'red. In numbers on leaf of wild cherry. 

 (After Beutenmuller). 



Classification of Insect Gulls 



The classification of galls is rather difficult and four methods 

 that have been suggested are here given. 



I. vSimple and Compound Galls. 



i. Simple galls: those galls that are limited to a single plant 

 organ. 



Fig. 7. Maple Spot Gall. 



Eye-like, circular, flat. Light yellow, with a red cen- 

 tral dot, or entirely green or yellow. In numbers on the 

 leaves of red maple. (After Beutenmuller). 



