EXPERIMENTS WITH THE DAISY ORGANISM. 27 



of tumors (the organism designated B). It was probabh' a third or 

 fourth subculture from the colony. Four of the inoculated white- 

 daisy shoots received 3 needle pricks each ; two received 1 prick each ; 

 one received 50 pricks. One to three check pricks were made in each 

 case, except on one shoot, which received 50 check punctures. 



The yellow-flowered daisies were each about 9 inches high and 

 limited to a single stem. Two of them received 1 infected prick each 

 near the top, with a check prick on each a little higher up on the 

 same side. Two of them received 3 infected pricks each near the top, 

 with 3 check pricks on each a little higher up. One received 30 

 infected-needle pricks up and down the stem. The sixth plant, held 

 as a check, received 50 punctures up and down the stem with a sterile 

 needle. 



Result. — February 23, 1907 : There was distinct evidence of infection 

 on each of the 12 shoots at the end of 5 days, the protuberances on 

 some bemg nearly a millimeter high.'* 



July : The plants were removed at the end of 1 month, 2 months, 

 and later with well-developed tumors. Galls formed only where inoc- 

 ulated. The 122 sterile (check) punctures healed normally. Every 

 infected prick resulted in a larger or smaller tumor. 



November 25: During the summer some of the plants developed 

 many secondary infections (metastases). 



Inoculations of December 19, 1907 (Brown). 



Seven young daisy plants were inoculated b}^ needle pricks on the 

 stem with agar streak cultures 2 days old. The Queen Alexandra 

 and a large yellow variety were used for these inoculations. 



Result. — January 28, 1908 : No galls were formed. The plants were 

 not in a growing condition, although they were young cuttings. 



Inoculations of March 12, 1908 (Smith). 



Five plants of the Paris daisy were inoculated with Bacterium 

 tumefadens from daisy on agar streak cultures 48 hours old. These 

 plants were inoculated as controls on the inoculations from the same 

 cultures into olive and oleander (pp. 31 and 34). 



Result. — May 21, 1908: All developed tumors promptly. Only 4 

 of the 5 plants now remain. They have good-sized tumors. 



Inoculations op February 11, 1908 (Brown). 



The crowns of 6 daisy plants were cleaned and inoculated by needle 

 pricks with a 2-day-old culture. The soil was then replaced over the 

 inoculated places. Three other plants were punctured on the crown 

 with a sterile needle for checks. 



a On older and slower-growing material inoculated by Miss Brown 12 days Ijefore the growth of the 

 tumors was slower and they were still incipient. 

 213 



