CAUSE AND NATURE <>F CROWN-GALL 



21 



KXPERIMENTS IN INOCULATING SOIL WITH MINCED GALLS 

 IN 1S97-1898. 



In conjunction with the experiments carried on at Glendale 

 a series of indoor experiments was begun in November, 1897. 

 These experiments were all conducted in the station green- 

 house at Tucson. 



November 24 two hundred almond seeds were planted in 

 good, porous soil, uniform in texture. The seeds were placed 

 in scalding water for a few moments prior to planting, in order 

 to facilitate germination, and then planted in plots on floor 

 benches, as outlined in the diagram. 



/ Z 3 H $ (, 7 8 3 10 11 72 13 1+ '*•'<* 17 1S '1 10 



Fig. 3.— Diagram representing the number and position of diseased and undiseased 

 almond seedlings grown in the green-house in 1897-189S. The small circles represent 

 the position of the seedlings and the crosses the diseased trees. 



The four plots were separated from each other by eight-inch 

 boards, set on edge and buried six inches in the soil. Fifty 

 seeds were planted in each plot, there being five rows with ten 

 seeds in each row. A number of the seedlings damped off soon 

 after coming up, and a few others died during the summer. 

 As those that died were pulled up and destroyed by the gar- 

 dener during my absence, I was unable to ascertain whether 

 they died from the effect of crown-gall. 



Plot I was planted without previous treatment of seeds or soil. 

 The purpose of this plot was to act as a check to the other three. 

 When the seeds were planted in plot II a number of galls ob- 

 tained from the Glendale orchard were cut into small pieces and 

 buried in the soil with them. The galls used in these experi- 



