EXPERIMENTS WITH THE HOP ORGANISM. 87 



Checks were held on sugar beet. Both chxisies and beets, especially 

 the former, were J^oung plants in excellent condition for inoculation. 



Result. — December 12, 1010: The subcultures from 12 of the 

 colonies proved to be noninfectious. Colony 1 produced galls on each 

 one of the 3 inoculated beets at the place of puncture. These tumors 

 were, respectively, ], 3, and 5 cm. in diameter at the end of 4 weeks, 

 when the experiment was interrupted. The largest gall was on the 

 most vigorous plant; the smallest was on a feeble plant. At this time 

 2 of the 4 daisies bore each a small gall on the pricked part. These 

 galls were 2 to 3 mm. only in diameter. The other plants were free. 



February 8, 1911: Three of the 4 daisy plants now bear tumors 

 where inoculated and not elsewhere. The smallest one is 1 cm. in 

 diameter, the largest one is 3 cm. 



Inoculations of November 30, 1910 (Smith). 



The preceding experiment was repeated on 12 young growing daisy 

 plants, using subcultures of the hop organism (colony 1) and inoculat- 

 ing from peptone bouillon cultures 16 days old. 



Result. — February 8, 1911 : Eight plants remained free, 4 developed 

 tumors at the place of inoculation and not elsewhere. These are now 

 one-eisrhth to one-half inch in diameter. 



o^ 



Inoculations of December 2, 1910 (Smith). 



A second repetition of the new hop (colony 1) on 20 daisy plants of 

 the same character, using agar streak cultures 2 days old, gave the 

 following : 



Result. — February 8, 1911: Seventeen plants free from tumors. 

 On 3 plants there are 4 tumors, the largest three-fourths inch in 

 diameter, the others one-fourth inch. 



HOP ON TOMATO. 



Inoculations of November 21, 1908 (Brown). 



Three tomato plants of a small, red, hothouse variety, 5 feet tall 

 and in fruit, were inoculated with the hop organism. The stems 

 about half way down the ])lant showed bulgings where roots might 

 possibly protrude and adventitious roots also projected a distance of 

 one-eighth to one-fourth inch. The bulging places on the stem and 

 the smallest adventitious roots were both inoculated with a^ar streak 

 cultures 3 days old. More than a dozen places on each plant were 

 punctured. Two check plants were held, the punctures being made 

 in the same way as those of the inoculati<ms. 



Result. — December 10, 1908: Galls formed at the bulged places on 

 the plants inoculated, but no hairy-roots. 



213 



