EXPERIMENTS WITH THE APPLE ORGANISM. 97 



dug into and plates poured (November 4). After 2 days they 

 yielded scattering saprophytic colonies of two types: (1) Whitish, cir- 

 cular, rather dense, of moderately rapid growth; and (2) larger, 

 dendritic white ones, consisting of a large nonmotile scliizomycete. 

 At this time there appeared to be nothing else on the plates, but 2 

 days later the plates came up thickly with small, round, while 

 colonies, and on the fifth day these had grown sufTicic^ntly so that 

 there appeared to be very httle doubt of their })eing the same sort of 

 organism that we had plated from the crown-gail of the peach. 

 These surface colonies were mostly less than 1 mm. in diameter, 

 wet-sliining, very translucent, white, circular; the buried ones were 

 elliptical. 



On November 9 transfers were made to agar streaks from 8 of these 

 small colonies. One of the characteristic plates was then selected 

 for the above inocidations. Plates were now made from the second 

 hard gall of the same lot, and these yielded similar colonies, with 

 which galls were also produced. 



Result. — November 16, 1908: As yet no indications of tumors on 

 any of these plants. 



July 22, 1909: Galls have appeared. The best growths are about 

 one-half inch in diameter and raised above the surface of the stem 

 one-fourth inch or less. The}' are typical liard galls. Only about 

 half the plants contracted the disease. This appeared at the inocu- 

 lated spots, and not elsewhere. The grovrths resembled the original 

 hard gall from which they were taken, rather than the ordinary daisy 

 gall (PI. Ill, bottom, stem 21). 



Inoculations of November 18, 190S (Smith). 



Three daisy plants were inoculated from colonies on poured plates 

 made November 9 from Iledgcock's second Iowa gall. At the time 

 of inoculation the small colonies were white, dense, fleshy, circular, 

 wet-shining. 



Result. — July 22, 1909: Galls on each one of the three plants 

 (PL III, bottom, stems 64, 65, 66). The growths are about one-half 

 inch in diameter, and raised above the surface of the stem one-fourth 

 inch or less. They are typical hard galls, i. e., not like the soft, rapid- 

 growing daisy galls. 



HARD GALL OF APPLE ON TOMATO. 

 Inoculations of December 4, 190S (Brown). 



The protruding adventitious roots of some nearly full-grown 

 tomato plants were inoculated with the ap})le gall organism obtained 

 from plates poured November 27. The ])rojections were well out 

 from the stem as though the roots were going to take hold of the soil. 

 The cultures used were agar slants 2 days old, the first subculture 

 78026°— Bull. 21:3—11 7 



