[Vor. 11 
86 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
commune, Pholiota adiposa, and Armillaria mellea fail to grow at 
Р н 7.0. 
This tendency to grow only in an acid medium is less evident 
in а more favorable nutrient, the peptone solution. Here іп every 
case growth is secured at P, 7.0, and only 4 species, Polystictus 
versicolor, Lenzites sepiaria, Pholiota adiposa and Daedalea con- 
fragosa, fail to grow in an alkaline solution. For these 4 species 
growth at P, 7.0 is much less than at more acid values. Three 
of the remaining 4 species, Schizophyllum commune, Pleurotus 
ostreatus, and Polyporus adustus, grow definitely on a slightly 
alkaline solution, the first 2 growing until Pa 8.5 is reached and 
the third until P, 8.0 is reached. Armillaria mellea in this case 
shows an intermediate condition similar to that obtained for 
Polystictus versicolor in the Richards’ solution. While Polyp- 
orus adustus and Pleurotus ostreatus are tolerant to а neutral 
substratum in the Richards' solution and to an alkaline substra- 
tum in the peptone solution, this is not true for Schizophyllum 
commune, which is distinetly intolerant to neutrality in the first 
case and more tolerant to alkalinity than any other species in 
the second. 
Of these fungi which were more tolerant to alkali, Schizophyllum 
commune and Pleurotus ostreatus are a little less tolerant to acid 
in the peptone solution than the other species, while Polyporus 
adustus is markedly more tolerant (table xv1). In the Richards' 
solution this relationship is not as distinct, for, while Schizophyl- 
lum commune retains indications of being less tolerant to acid, 
Pleurotus ostreatus and Polyporus adustus differ little or not at 
all from the other 5 fungi. On the other hand, of those species 
which show no indication of growth in alkaline solution, Lenzites 
sepiaria and Pholiota adiposa react as do the majority with 
reference to acid tolerance, while Polystictus versicolor shows 8 
wider range оп the acid side іп the Richards’ solution. Armillaria 
mellea exhibits a wider range on the acid side in the peptone 
solution. In other respects these 2 species do not differ from the 
majority. 
The data obtained from these experiments have shown that | 2 
mycelial growth of Polystictus versicolor, Lenzites sepiaria, Pho- — 
hota adiposa, Armillaria mellea, and Daedalea confragosa i8 — | 
