556 



BACTERIAL DISEASES OF PLANTS 



Fig. 417.— Monothalamous galls due (?) to Andricus topiarius Ashmead, on a 

 Washington, D. C, oak, said to be Quereus prinus, showing tufts of linear leaves 

 resembling the leaves of the willow oak (Q. phellos). Probably what is known in the 

 older literature as Cynips frondosa. These tufts grow from the tissue immediately 

 below the gall. 



