MISCELLANEOUS: STIMULI UNDERLYING TUMOR-FORMATION 557 



f 



B 



FIG. 418. A. Like Fig. 417 but with many of the linear leaves removed so as 

 to show the smooth white gall which seems to occupy the place of a bud. B. 

 Vertical section of a similar gall showing a single larva in place. Planar 

 enlargements. 



