ATTACKING THE LEAVES. 



293 



myia, and on cutting into the galls they are found to be hollow, 

 each containing a pale-orange larva. It is probable that the 

 larva enters the earth to transform to the chrysalis, and that 

 the fly is produced the following season. 



No. 167. — The Grape-vine Filbert-gall. 



Vitis coryloides Walsh & Riley. 



In this instance a rounded mass of galls from one and a 

 half to two and a half inches in diameter springs from a 

 common centre at a point where a bud would naturally be 

 found. The mass (see Fig. 304) is composed of from ten to 



Fig. 304. 



forty opaque, woolly, greenish galls, which have a fleshy, juicy, 

 sub-acid interior, each with a single central, longitudinal cell, 

 one of which is shown at c in the figure, about a quarter of 



