Studii^s on Crown Gall of Plants 433 



same ort^anism (B) was isolated by poured plates from one of the ,t;alls 

 and its infectious nature proved by [subsequently described] inoculations."^ 



On February IS, 1907, Smith began experiments to verify and 

 extend what had been done. His memoranda read: 



Four vigorous plants of white flowered Paris daisy and 6 similar plants 

 of the yellow-flowered Paris daisy were selected. Each plant of the white 

 variety branched at the base into two et]ual shoots; 7 of these shoots were 

 inoculated and the eighth was held as a check. On the inoculated shoots 

 also check pricks were made .m inch or two above the places where the 

 infected needle entered. All of the inoculations were made by needle pricks, 

 usin£j a slant clyccrine-a^^ar culture, 7 days old, which had been streaked 

 from another slant at;ar culture. The ori^anism was derived from a strain 

 which had been passed twice through the daisy by Miss Brown with the pro- 

 duction of tumors (the organism designated B). It was probably 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. . . . 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 being nearly a millimeter high. 



During and from July, the " plants were removed at the end 

 of 1 month, 2 months, and later, with well-developed tumors. 

 Galls formed only where inoculated. The 122 sterile (check) 

 punctures healed normally. Every infected prick resulted in a 

 larger or smaller tumor." By November 25, he added, " During 

 the summer some of the plants developed many secondary infec- 

 tions (metastases) ." "''" 



This appears to have been his first experiment using the daisy 

 organism on daisy, and on February 18 he started other similar 

 experiments using the daisy organism on tomato and tobacco. 

 Experiments with the daisy organism, and with schizomycetes 

 from galls on other plants, would be made on a wide variety of 

 cultivated plants. Hard and soft galls would be studied according 

 to t)'pe, distribution, cause, technique in study, cultural characters, 

 histology, transmission, variability, etc. The work would bring 



^^ Crown-gall of plants: its cause and remedy, op. cit., 25. Miss Brown's sets of 

 inoculations here referred to were started on January 8 and 18 and Februar>' 6, 1907. 

 Scientists interested in this subject should read the description of the technique 

 applied by Miss Haskins (pp. 22-25) and compare this with pp. 25 et seq., 

 " Further inoculations by [Smith, Brown, and Townsend] made with the daisy 

 organism and with the same or similar bacteria plated from galls on other host 

 plants." 



^* Crown-gall of plants: its cause and remedy, op. cit., 26-27. 



