42 CEOWN-GALL OF PLANTS. 



DAISY ON BLACKBEERT. 



Inoculations op April 11 and 12, 1907 (Smith and Brown). 



Thirty-four blackberry plants, 17 of Ena variety and 17 of the Kath- 

 bon variety, were inoculated with agar streak cultures of the daisy 

 organism, the former with 5-day-old cultures, the latter with 6-day- 

 old cultures, each plant receiving 15 to 20 punctures. Seven checks 

 were held of each variety. The surface of the streak cultures used 

 for these inoculations was smooth and wet-shining; they had not 

 spread very widely over the surface of the streak — widest, however, 

 near the fluid in the V. The fluid itself was thinly clouded, except 

 at the top, w^hich had stringy white masses of bacteria. The inocula- 

 tions were made in the laboratory and the plants immediately after- 

 wards set out in pots in the greenhouse. The plants were obtained 

 from Virginia. 



Result. — June 27, 1907: Three of the Eathbons dug; no tumors. 

 One was dead when dug. 



July 3, 1907: The remainder of the inoculated blackberry plants 

 were dug and the roots examined. No tumors were found. Twenty 

 of the plants were dead. The others had made a moderate growth. 



DAISY ON APPLE. 



Inoculations of April 13, 1907 (Smith). 



Three varieties of apple (2 trees of each) were inoculated with the 

 daisy organism, each tree receiving 30 pricks, in groups of 5. The 

 varieties were as follows: Baldwin, Early Harvest, Ben Davis (No. 

 386 had hairy knots on its roots, which were pruned off). 



Six trees were held as checks, each receiving 30 pricks in groups 

 of 5, as follows: 2 Baldwin; 2 Early Harvest, 2 Ben Davis. 



Result.— June 28, 1907: Early Harvest, No. 382— A few slight 

 calluses on the cut surface of the root; no indication of galls in the 

 pricked areas or elsewhere. Baldwin, No. 358 — Similar to the pre- 

 ceding; nothing suggestive of tumors. Ben Davis, No. 386 — Much 

 more decided evidences of tumors; nearly every root which was 

 pruned back has an abnormal amount of callus, resembling a gall, on 

 its cut surface, and there are also some little galls on one root; no 

 evidence of any tumors where the needle entered — in fact, it is 

 difficult to find where the needle did enter. 



July 13, 1907: The remainder of the apple trees inoculated April 

 13, 1907, were dug, the roots washed and examined for galls. Con- 

 dition of roots as follows: Early Harvest, No. 381 — Badly over- 

 grown calluses. Ben Davis, No. 387 — Very badly overgrown calluses, 

 seven of them. Baldwin, No. 357 — Overgrown calluses. 



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