EXPERIMENTS AVITH THE DAISY ORGANISM. 31 



Inoculations of March 20, 1907 (Brown). 



Six tobacco plants were inoculated on the stems and leaves by 

 needle pricks with agar streak cultures 2 days old. One plant was 

 held as a check. 



Eesult. — Ajiril 12, 1907: Knots a half inch in diameter had formed 

 on all of the inoculated plants on leaves as well as stems. The check 

 remained free. 



Inoculations of September 19, 1907 (Brown). 



Six tobacco plants were inoculated by needle pricks on the stems 

 with 3-da3^-ol(l agar slant cultures. Four plants were held as checks. 



BesuU.—Octoher 25, 1907: The inoculated stems all bore knots; 

 there were none on the checks. 



DAISY ON OLEANDER. 



Inoculations op May 6, 1907 (Brown). 



The stems of 3 oleanders were inoculated with agar streak cultures 

 2 days old; two checks were held. The plants were small and not 

 in very good condition. 



Result. — March 4, 1907: Small galls are visible. 



July 19, 1907: Galls had formed on the inoculated plants where 

 punctured, but they were not very large, i. e., not over half an inch 

 in diameter; none appeared on the checks. 



Inoculations of March 5, 1908 (Brown). 



Four young shoots of single white oleander were inoculated by 

 needle pricks with agar streak cultures 2 days old; two checks were 

 held. 



Result— MsiTch 18, 1908: Galls had formed on all the places inocu- 

 lated. The checks remained free from galls. 



Inoculations of March 7, 1908 (Smith). 



Six oleander plants were inoculated with agar slants 48 hours old. 

 Result. — June 1, 1908: All produced tumors. 



Inoculations of March 12, 1908 (Smith). 



Ten plants were inoculated with agar streak cultures 48 hours old 

 of Bacterium tumefaciens from Paris daisy. The oleander plants were 

 of three varieties: Madam Peyre, Professor Parlatore, and Single 

 White. They were in excellent condition, 7 out of 10 of them having 

 double shoots from the roots (young wood), 1 shoot lower and 

 younger than the other; the other 3 bore single shoots. Where 2 

 shoots came from the same root or stem base, the lower, younger one 



213 



