176 BACTERIAL DISEASES OF PLANTS 



to have been brought on infected seed. No one has yet isolated 

 it from the soil, nor do we know that it persists in soils. 



MEANS OF PREVENTION 



This disease is disseminated almost exclusively by the seed- 

 trade. When growers of seed-corn have learned to recognize it 

 and refuse to market corn from fields in which it has been 

 prevalent, the disease will almost entirely disappear. Mean- 

 while, seed-corn may be rendered nearly free from the organism 

 by plunging it for a moment into alcohol and then for 15 

 minutes into 1:1000 mercuric chloridcwater, whereupon it may 

 be rinsed in water (for a moment only) and then spread out to 

 dry, or planted at once. 



LITERATURE 



Read Stewart's Bulletin No. 130, Geneva, N. Y. Experi- 

 ment Station, which is the first paper. 



Consult Stewart's Disease of Sweet corn (Maize) in " Bac- 

 teria in Relation to Plant Diseases," Vol. Ill, pp. 89-147; also 

 Ibid., Vol. I, Figs. 1, 73, 74, 75; and Vol. II, Fig. 14 and Plate 

 17. The organism was first named by the writer Pseudomonas 

 stewarti in 1898 in. Proc. Am. Asso. Adv. Sci., Vol. XLVII, 

 pp. 422-426. 



