EXPERIMENTS WITH THE PEACH ORGANISM. 65 



This is in the same set of inoculations as that of the Wealthy apples, 

 which took the disease (PI. XII, fig. 2), and the 2 daisies which did 

 not take it. 



November 16, 1908: No tumors. 



PEACH ON PHLOX. 



Inoculations op May 18, 1909 (Brown). 



Young annual phlox plants in pots just starting to bloom were 

 inoculated near the tips of the stems by needle pricks with agar cul- 

 tures 4 days old of the peach-gall organism (isolated February 29, 

 1908). Ten plants were inoculated and 4 were held as checks. 



Result. — June 8, 1909: No indications of galls could be seen. 



July 14: Examined again — no galls. The cultures may have lost 

 their virulence. 



PEACH ON VERBENA. 



Inoculations op May 18, 1909 (Brown). 



Young verbena plants growing in pots were inoculated with 4-day- 

 old agar cultures of the peach-gall organism (isolated February 29, 

 1908), the stems being pricked at the tips, at the base, and midway 

 between. Ten plants were inoculated and 4 were held as checks. 



Result. — July 14: No indication of galls. 



PEACH ON GRAPE. 



Inoculations of June 24, 1910 (Smith and Brown). 



The terminal part of 2 green shoots of Vitis vinifera was inoculated 

 by needle pricks from a 2-day-old agar streak culture of the crown- 

 gall organism from the peach (isolated February 29, 1908). 



Result. — July 18, 1910: Doubtful; only slight prominences. 



October 31, 1910: Nothing on one; very tiny elevations in needle 

 pricks on the other; no true galls. Organism had probably lost 

 virulence. 



PEACH ON IMPATIENS. 



Inoculations op June 24, 1910 (Smith and Brown). 



One pink-flowered plant on 3 shoots and 1 white-flowered plant 

 on 2 shoots were inoculated by needle pricks from 48-hour-old agar 

 streaks of the crown-gall of peach organism (isolated February 29, 

 1908). The stems were soft. 



Result. — October 21, 1910: All negative. 

 78026°— Bull. 213—11 5 



