CAUSK AND NATURE OF CROWN-GALL 



45 



or ten days, numerous pustules of gall tissue frequently begin 

 to form on the cut surface or on the under margin of the old 

 gall. If kept under proper conditions, the young galls con- 



FlG. 23.— Section through the large parenchyma cells adjacent to the surface of the 

 gall, showing the large intercellular spaces and the cells partially filled with finely 

 reticulated, rather dense masses of vacuolar protoplasm. (Magnified same as scale- ; 

 scale = 10 /u..) 



Fig. 24. Same as Fig 23, with the exception that the drawing was made an half 



hour later. (Magnified same as scale ; scale = 10 p..) 



tinue to grow for days or even weeks or until the store of starch 

 in the old tissue is exhausted. If the mature gall be cut open 



