S. G. Paine 219 



SUMMARY. 



A disease of cultivated mushrooms is described in which patches of 

 a chestnut brown colour so disfigure the pileus as to render the affected 

 crop quite unmarketable. 



The disease is identical with that described in America by Tolaas, 

 but left unnamed by him. 



The cause of the disease is a small bacterial parasite which may 

 possibly be a strain of Pseudomoims fluorescens and may prove to be 

 identical with the organism which produces Pear-blossom Blight. 



Until its identity is established by further experiment it seems well 

 to give it a distinguishing mark, and the name Pseudomonas Tolaasi is 

 suggested. 



REFERENCES. 



(1) Barker, R. T. P. and Grove, 0. A Bacterial Disease of Fruit Blossom. Ann. 



App. Biol. vol. I, 1914-15, p. 85. 



(2) DoiDGE, E. M. A Bacterial Blight of Pear Blossoms occurring in South Africa. 



Ann. App. Biol. vol. iv, 1917, p. 50. 



(3) Grove, 0. Notes on the Fruit Blossom Bacillus. Ann. Report Agri. and Hart. 



Research Sta., Long Ashton, Bristol, 1917, p. 21. 



(4) Jensen, H. Versuche iiber Bakterienkrankheiten bei Kartoffeln. Centralbl. f. 



Bah. Abt. ii, Bd. vi, 1900, S. 641. 



(5) Morse, W. J. Studies upon the Blackleg Disease of the Potato with Special 



reference to the Relationship of the Causal Organism. Jour. Agri. Research, 

 vol. \^ii, 1917, p. 79. 



(6) Tolaas, A. G. A Bacterial Disease of Cultivated Mushrooms. Phytopathologu, 



vol. V, 1915, p. 51. 



