552 
AMERICAN JOURNAL OF BOTANY 
[Vol. io. 
justed to pH 2.2 was very light and caused no change in the reaction of the 
medium. The fungus grew well at all hydrogen-ion concentrations from 
pH 2.8 to 8.4. Growth at pH 2.8 in one case caused a slight change in the 
reaction of the medium toward greater alkalinity. At all hydrogen-ion 
concentrations from pH 3.6 to 8.4, the growth of the organism was accom¬ 
panied by changes toward greater acidity. 
Department of Plant Pathology, 
University of Wisconsin 
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