NOTES ON PARASITIC FUNGI IN WISCONSIN—X 
J. J. Davis 
The season of 1921 was characterized by high temperature and 
low humidity and was consequently unfavorable for the develop¬ 
ment of most fungous parasites. The low stage of water in the 
Wisconsin River, however, gave opportunity to explore bottom 
lands that are ordinarily difficult of access. 
After one’s conceptions of generalities have changed, there is a 
lag in the application of such changes to particulars. When the 
writer began the collection of data on the parasitic fungus flora 
of Wisconsin there was in his mind a conception of such a flora as 
something fixed, static; given time and application it could be 
fully set forth. The fact of quantitative variation was quickly 
brought home to him and was expressed in his first contribution. 
More slowly the conception of vegetation as dynamic and mutable 
has come to be applied to a special group in a local flora. The 
records are then seen as datum points having a time as well as a 
space value. This conception increases rather than lessens their 
value but shows no finality as a goal. It does not however at all 
lessen the importance of completeness in the record. 
The downy mildews as they occur in Wisconsin are interesting 
from an evolutionary viewpoint. Typically they bear two kinds of 
spores, summer dispersion conidia and winter resting oospores, and 
cause local infections. In many species, however, general infec¬ 
tion takes place and allows overwintering as mycelium. Such spe¬ 
cies show a tendency toward suppression of oospores and abun¬ 
dance of conidia. In Plasmopara pygmaea (Ung.) Schroet. each 
of these directions of change seems to have been followed. On 
Hepatica and Anemone quinquefolia and A. canadensis races pro¬ 
ducing local infections and both kinds of spores; on Anemone quin¬ 
quefolia a race with general infections and suppression of oospores; 
on Hepatica acutiloha local infections, abundance of oospores and 
no conidia. The latter is what Peck described under the name 
Protomyces fuscus but which I have designated Plasmopara pyg- 
