1924] 
WOLPERT—FUNGI AND H-ION CONCENTRATION OF MEDIA 47 
fungi. Beet decoction gave the best percentage and range of 
germination and “water H;PO, and NaOH" the poorest. He 
observed that in equal concentrations the OH ions are more 
toxic to the spores of the fungi studied than are the Н ions. His 
results indicate that the range and percentage of germination, 
as influenced by the hydrogen-ion concentration, depend upon 
both the organism and the medium, and that the direction and 
magnitude of the change in the reaction of the medium due to 
spore germination depend upon the fungi, the medium, and 
the initial reaction of the solution. 
METHODS 
Organisms.—In the selection of organisms, З things were con- 
sidered: (1) the use of as many representative genera as possible, 
(2) the use of species found commonly both on deciduous woods 
and on eoniferous woods, and (3) the use of forms which grow 
well upon artificial media. With these considerations in mind, 
the following 8 species were selected: Polyporus adustus (Willd.) 
Fr., Polystictus versicolor (L.) Fr., Pleurotus ostreatus Jacq., 
Sehizopiilum commune Fr., Pholiota adiposa Fr., Lenzites sepiaria 
(Wulf.) Fr., Armillaria тейге (Vahl) Quel., and Daedalea con- 
fragosa (Bolt.) Fr. 
These species are common wherever their respective hosts are 
found. Preliminary work has shown them to make more rapid 
growth in artificial culture than many other common fungi. 
Weir (14) found that Armillaria mellea is common both on 
deciduous and on coniferous woods; that Lenzites sepiaria is 
confined almost entirely to coniferous species, whereas Poly- 
stictus versicolor and Polyporus adustus are usually upon deciduous 
species but are found occasionally upon coniferous hosts. Pholi- 
ota adiposa is found on Abies grandis as well as on some deciduous 
trees. Schizophyllum commune, common on deciduous woods, 
according to Rhoades (’21), occurs occasionally upon coniferous 
hosts. Daedalea confragosa and Pleurotus ostreatus are ed 
as saprophytic upon deciduous woods. 
Pure culture methods.—Pure cultures were made by employing 
either the tissue-culture method described by Duggar ('05) or 
the spore method used by Zeller (716). These methods have 
