EXPERIMENTS WITH THE GKAPE ORGANISM. 55 



back from the root and the crown inoculated by needle pricks. 

 Three checks were held. 



Result.— J Sinusivy 4, 1910: Four of the 9 plants had tiny galls. 

 The checks were free. The plants had grown scarcely any since the 

 time of inoculation. 



COTTON ON SUGAR BEET. 



Inoculations of November II, 1909 (Brown). 



Nine young sugar beets were inoculated at the crown with 5-day-old 

 agar cultures of the cotton-gall organism, using needle pricks. The 

 beets were young and growing in the open bed. 



Result. — January 4, 1910: No galls. 



March 7: Plants were pulled up — no galls. 



Inoculations of July 5, 1910 (Brown). 



Six young sugar beets were inoculated with 4-day-old agar cultures 

 of the cotton-gall organism, using needle pricks. 



Result. — July 18, 1910: No galls. The beets grew very slowly, 

 owing to the excessive heat. 



GRAPE ON DAISY. 



Inoculations of March 28, 1908 (Smith). 



Sixteen daisy plants were inoculated from slant agar cultures of 

 March 25, the organism being derived from a tumor on grape occur- 

 ring in this country. The plants had not yet branched and were in- 

 oculated in young and tender shoots about 6 to 8 inches from the 

 ground. 



Result. — June 1, 1908: They have given no distinct tumors, but 

 a much more corky development than would have resulted from the 

 needle punctures alone. The plants are now in blossom. These 

 plants may have been cuttings taken from somewhat resistant tumor- 

 bearing plants, or it may not have been the right organism, or, finally, 

 colonies derived from an organism of weak virulence may have been 

 used. 



Inoculations op August 31, 1909 (Brown). 



Six young daisy plants of a strain that had never been inoculated 

 with any gall organism were inoculated with grape-gall organism 4 

 days old (used also for inoculating sugar beet and grapevines). The 

 plants were very small, still in .3-mch pots, and had very Uttle soft 

 tissue. Eight checks were held. The plants were repotted after in- 

 oculating. 



Result. — October 13, 1909: Tlu-ee of the 6 daisy plants had galls. 

 These galls resembled the regular daisy gall and looked unhke those 

 of grape, owing, perhaps, to different tissue reaction of the plants. 



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