478 Journal of Agricultural Research voi. iv, No. s 

 .1 



be of little consequence, no extensive study was made. There is no 

 description of his organism. 



F. L. Stevens (1908), in a short report on a bacterial disease of lettuce, 

 states that the bacteria isolated were rather long rod forms. His attempts 

 at inoculation were unsuccessful. 



H. S. Fawcett (1908) also reports a bacterial disease of lettuce. He 

 likewise isolated an organism and reproduced the disease. His colonies 

 on standard peptonized agar had indefinite margins and pearl-white 

 foci. The organism stained readily in carbol fuchsin and aqueous 

 gentian violet, but with difficulty in methylene blue. 



O. F. Burger (1912) describes a bacterial disease of lettuce which he 

 says is caused by a species of Pseudomonas. The disease begins at the 

 center of the head, which blackens and then becomes soft. In the 

 seed bed the disease appears as small black spots on the leaves. This 

 does not seem to be the type of disease that occurred in Louisiana this 

 year. Burger states that cultures of the bacteria were made and healthy 

 lettuce plants were inoculated. In 10 days the inoculated plants were 

 black and pulpy, while the checks were still healthy. 



Bacteriutn viridilividum does not agree with the descriptions of any of 

 the organisms mentioned by these writers. Voglino's (1904) organism 

 evidently does not liquefy gelatin, and the colonies in lettuce gelatin 

 change from an ivory-white color to a rosy tint. B. viridilividum 

 liquefies gelatin, and is never ivory white or of a rosy tint. Fawcett's 

 (1908) organism produces colonies with indefinite margins and pearl- 

 white foci and stains with difficulty in methylene blue. B. viridilividum 

 has definite margins, no pearl-white foci, and stains readily in methylene 

 blue. Stevens's (1908) organism is a long rod form; B. viridilividum is 

 a short rod. Stevens's inoculations were not successful. Jones (1893), 

 Brooks (Stone, 1907), and Burger (191 2) did not describe their organisms. 



LITERATURE CITED 

 Burger, O. F. 



1912. Lettuce rot. Fla. Agr. Exp. Sta. Press BuL 200, 2 p. 

 F.\WCETT, H. S. 



1908. Lettuce disease. In Fla. Agr. Exp. Sta. Rpt., [i907]/o8, p. Ixxx-lxxxvii, 



pl- 4-5- 

 Jones, L. R. 



1893. A bacterial "stem-rot" of lettuce. In Vt. Agr. Exp. Sta. 6th Arm. Rpt., 

 1892, p. 87-88. 

 Stevens, F. L. 



1908. A serious lettuce disease. 7nN. C. Agr. Exp. Sta. 30th Ann. Rpt., [i9o6]/o7, 

 p. 72. 

 Stone, G. E. 



1907. Bacterial disease of lettuce. In Mass. Agr. Exp. Sta. 19th Ann. Rpt., 

 [1906], p. 163-164. 

 VoGLiNO, Pietro. 



1904. Sulla batteriosi delle lattughe. In Ann. R. Accad. Agr. Torino, v. 46, 

 1903, p. 25-33, 4%- 



