18 CROWN-GALL OF PLANTS. 



proofs. In the same way Laubert and Kock in Austria have ascribed 

 the rose canker to Coniothyrium (1905). 



Stoklasa in Bohemia ascribed the beet gall to nematodes (Tylen- 

 chus) and Bubak in Austria to mites (Histiostoma), but nematodes 

 and mites are present in true crown gall, so far as we have observed, 

 only after decay sets in. Possibly Stoklasa had to do with nematode 

 galls which also occur on the beet. (PI. IV, fig. 1.) 



This disease, as it appears on the vine, is known in France as 

 Broussins, in Ital}^ as Rogna, and in Germany as Krebs or Grind. 

 Viala also gives various other names, as Exostoses, Exostoses fon- 

 goides, Fongosites, Raude, Kropf, Schorf, Ausschlag, Mauke, Hanab, 

 Tubercoli, Malattia dei tubercoli, etc. The gall on the sugar beet is 

 known in Germany as the Wurzelkropf. 



This brings the European history of crown-galls, so far as ascribed 

 to bacteria, down to the appearance of the first paper on the subject 

 by the senior writers of this Bulletin in April, 1907 (Science), a trans- 

 lation of which, with some additions, was published in Germany. 

 (Centralb. fiir Bakt. 2 Abt., Bd. 20, December, 1907, p. 89.) 



In 1907, Ugo Brizi, of Milan, described and figured a tumor of 

 poplar, ascribed the disease to bacteria, claimed infections with 

 pure cultures, and named and described a yellow schizomycete 

 {Bacillus 'po'puli) said to be the cause of the galls (Atti Congreso 

 Naturalisti Italiani, Milan, June, 1907). The Congress was held in 

 September, 1906, but the paper was not published until the following 

 summer. 



Brizi figures one infection only and gives no details concerning his 

 inoculation experiments, i. e., where they were conducted; how many 

 failed; how many checks were held; and whether any of the latter con- 

 tracted the disease. His experiments are probably of the same sort 

 as Professor Toumey's, where one known organism was introduced and 

 another unknown (and unsuspected) organism actually caused the 

 disease. 



The Bacillus populi of Brizi, which is probably one of the yellow 

 saprophytes common in crown-galls, may be distinguished readily 

 from the organism described in this bulletin by the following charac- 

 teristics, which are summarized from his paper: 



Yellow growth on culture media (agar, gelatin, potato, sugar beet, 

 etc.) ; production of spores, which are generally in one end, which is 

 swollen and refringent; rapid production of indol (24 hours at 30° C.) ; 

 rapid coagulation of milk (12 hours at 25° C.) and re-solution of the 

 curd; rapid growth in weakly acid beef broth at 25° C, i. e., clouding 

 after a few hours. Motility occurs, but he did not succeed in demon- 

 strating flagella by means of stains. Inasmuch as he has lost his 

 cultures of this organism (letter of Brizi to Krdl, Sept. 2, 1910), we 

 were unable to obtain it for comparison. 



213 



