388 Journal of Agricultural Research voi. xiii.no. 7 



It appears that both of these organisms are present and active in soil 

 in which there is abundant green manure or stable manure which has 

 not been thoroughly decomposed. If conditions are such that the plant 

 keeps up a steady growth and is not checked, these bacteria do not enter. 

 When conditions are such that the plant is weakened or growth checked, 

 an entrance is gained and disease follows. 



The marginal disease of greenhouse lettuce reported from Kansas is 

 also caused by a soil bacterium. The name "Bacterium marginale" is 

 suggested. The margins of the inner whorl of leaves of immature plants 

 are most frequently infected, but the entire leaf can be speckled or spotted 

 by infection, which depends on defective greenhouse conditions. Sub- 

 rrigation and proper ventilation will prevent this disease. 



LITERATURE CITED 

 i) Jones, L. R. 



1893. A BACTERIAL "stem rot" OF LETTUCE. /« Vt. Agf. Exp. Sta. 6th AlUl. 



Rpt. 1892, p. 87-88. 



2) VoGLiNO, Pietro. 



1904. SULLA BATTERiosi DELLE LATTUGHE. In Ann. R. Accad. Agr. Torino, 

 V. 46, 1903, p. 25-33, 4fig- 



3) Stone, G. E. 



1907. BACTERIAL DISEASE OF LETTUCE. In Mass. AgT. Exp. Sta. 19th Ann. Rpt. 



1906, p. 163-164. 



4) Stevens, F. L. 



1908. A BACTERIAL DISEASE OF LETTUCE. In N. C. Agf. Exp. Sta. 30th Ann. 



Rpt. [i9o6]/o7, p. 29-30. 



5) Fawcett, H. S. 



igoS. LETTUCE DISEASE. In Fla. Agr. Exp. Sta. Rpt. [i907]/8, p. LXXX- 

 Lxxxvii, pi. 4-5. 



6) Burger, O. F. 



1912. LETTUCE ROT. Fla. Agr. Exp. Sta. Press Bui. 200, 2 p. 



7) 



1913. A BACTERIAL LETTUCE DISEASE. In Fla. Agr. Exp. Sta. Rpt. [i9ii]/i2, 



p. xcvni-c. 



8) Brown, Nellie A. 



1915. A BACTERIAL DISEASE OF LETTUCE. In Jouf. Agr. Research, v. 4, no. 5, 

 p. 475-478. Literature cited, p. 478. 



9) Carpenter, C. W. 



1916. RIO GRANDE LETTUCE DISEASE. In Phytopathology, v. 6, no. 3, p. 303- 

 305. I fig- 



