VOLUME XLVIII NUMBER 1 
BOTANICAL. GAZETTE 
JULY s909 
VARIATION OF FUNGI DUE TO ENVIRONMENT? 
F. L. STEVENS AND J. G. HALL 
(WITH THIRTY-SEVEN FIGURES) 
The effects of environment, climatic condition, soil fertility, the 
presence of unusual chemicals, the water relation, and what not, 
upon the form and characters of seed plants, are well known to the 
plant physiologist, and have been the subject of numerous studies. 
These factors are even utilized by the practical man to bring about 
desired variation. 
That fungi vary similarly will not be doubted any who have had 
to do with fungi in artificial cultures. The kind and degree of such 
variation, we dare say, will be a surprise to any who have not made 
special study of this subject. 
Our knowledge of the seed plants, owing to man’s long acquaint- 
ance with them, their larger size, and comparative stability, is con- 
siderable; yet even with them the limiting of genera, species, varieties, 
etc., presents difficulty, if we may judge from the rich literature upon 
phanerogamic taxonomy. ‘The fungi, because of their immense num- 
ber of species, variety of forms, minuteness, paucity of distinguishing 
characters, complexity of life-history (mostly unknown), peculiar 
biologic host relations (almost entirely unknown), and because of 
man’s short acquaintance with them and their unknown but appar- 
ently vast range of variability, present as yet baffling problems of rela- 
tionship and classification. 
The object of the present paper is to call attention to the kind and 
degree of environmental variation found in a few species of fungi that 
have been studied by the authors during the past four or five years, 
Read in part at the Baltimore meeting of the Botanical Society of America, 
December, 1908. 
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