CAUSE AND NATURE OF CROWN-GALL 



93 



In plot IV but one diseased seedling was found, and that in 

 the extreme corner adjacent to the plot treated with sulphur. 

 The results with this plot certainly suggest the value of blue- 

 stone as a remedy. 



Fig. 4. — Diseased almond seedlings resulting from inoculating soil with minced galls 



in 1897-1S9S. 



EXPERIMENTS IN INOCULATING HEALTHY SEEDLINGS BY 

 MAKING INCISIONS THROUGH THE BARK AND INSERTING 

 BITS OF THE YOUNG GALL, 1897-1S98. 



Twelve of the seedlings grown in plot I of the previous 

 experiments were cut back to within three inches of the sur- 

 face of the ground and reset in the same plot in which they 

 grew. Before resetting a small incision was made at the crown 

 of each plant, and a bit of young gall, carefully removed from 

 the interior of a growing specimen, was inserted. These seed- 

 lings were reset October 24, 1898, and on examination a mouth 

 later ten of them had rapidly developing galls at the places 

 where the incisions were made. November 30 of the same 

 year four perfect seedlings were cut back and reset as before. 

 The incisions, however, were made both at the crown and at a 



