VAN BREDA DE HAAN'S WILT OF PEANUT. 



153 



of the disease the bacteria had spread also into the vessels and into the parts of the plant 

 above the ground. The bacteria were not found in the leaf-stems or the fruit-stems, but 

 in the wood of the main stem and of the lower branches. In the attacked parenchyma- 

 cells the starch had disappeared. No other harmful organisms were found on the inside of 

 the diseased plants. The death of the plant, therefore, is ascribed to the presence of the 

 bacteria in the wood parenchyma and in the wood vessels. "The hama wedang must thus 

 be a root-disease caused by bacteria. * * * Some plants show a predisposition to the 

 disease. This greater susceptibility to the hama wedang, I think, must be ascribed largely 

 to the use of inferior seed. " The growers do not reserve their own seed, but sell the entire 

 crop and buy their seed from the Chinese merchants, who supply seed which represents the 

 inferior product, less desirable for the oil-mills. 



The organism was not cultivated and no measurements are given. 



Through the courtesy of Dr. van Breda de Haan the writer received alcoholic material 

 of peanuts affected by this disease, and a study of these has enabled him to show the gen- 

 eral morphology of the schizomycete and its relation to the tissues of the host-plant (figs. 68, 

 69, 70, and 71). There is no reasonable doubt that it is a genuine bacterial disease, nor that 

 it should be classed among those acting through the medium of the vascular bundles. 



Since this text was prepared for publication, Honing, in Sumatra, has reported the 

 occurrence there of a bacterial disease of the peanut (probably this one), which he attributes 

 to Bacterium solanacearum (for literature see "Wilt of tobacco"), and in the winter of 

 1912-13 Fulton, of North Carolina, stated that this same organism causes a disease of the 

 peanut in that State (Annual meeting Am. Phytopathological Society, at Cleveland, Ohio). 



LITERATURE. 



1906. Breda de Haan, J. van. Rapport over Ziekte 

 in den aanplant van Arachis hypogwa (Kat- 

 jang holle) in de Afdeelingen Koeningan en 

 Cheribon der Residentie Cheribon. October 

 1905. Teijsmannia, Batavia, vol. 17, I96. 

 pp. 52-63- 



191 1. Honing. 

 1913 



(See under Tobacco Wilt.) 



(See under 



Fui.ton, H. R, and JR. Winston 

 Tobacco Wilt.) 



