[Vor. 11 
94 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
peptone-nutrient, and cellulose-nutrient media at different tem- 
peratures have been studied. The limits of Py, optimum Рн 
холе, optimum temperature, and changes in the active acidity 
of the solution due to growth have been determined for each of 
these species. In addition the utilization by these fungi of strips 
of filter-paper and of celluloses from white oak, pine, sugar maple, 
and poplar woods has been studied. 
Under the conditions of these experiments it is possible to 
draw the following conclusions: 
(1) Тһе range of Рн in which these fungi will grow and the 
amount of mycelial growth depend upon the individual organism, 
the composition of the nutrient solution, the initial active acidity 
and the temperature. 
(2) The major portion of the growth curves of all of these fungi 
is on the acid side of neutrality and in the majority of cases 
wholly on the acid side. 
(3) In the Richards’ solution the Py which inhibit growth are: 
Lenzites sepiaria, 3.4 and 7.3; Daedalea confragosa, 3.5 and 7.2; 
Polystictus versicolor, 2.5 and 7.6; Armillaria mellea, 2.9 and 7.4; 
Pholiota adiposa, 2.8 and 7.0; Polyporus adustus, 3.5 and 7.6; 
Pleurotus ostreatus, 3.0 and 7. 5; Schizophyllum commune, 3.4 
and 7.0. 
(4) Moreover, in the Richards' solution Polunorus adustus, Schi- 
zophyllum commune,and Pleurotus ostreatus grow when the medium 
is neutral. Бораны versicolor is less tolerant to а neutral solu- 
tion, while the other 4 species are inhibited by this hydrogen- 
ion concentration. 
(5) In the peptone solution the Рн which inhibit growth are: 
Polyporus adustus, 2.0 and 8.0; Daedalea confragosa, 2.8 and 7.6; 
Polystictus versicolor, 2.5 and 7.5; Armillaria mellea, 2.0 and 
7.8; Pholiota adiposa, 2.8 and 7.8; Lenzites sepiaria, 2.8 and 7.5; 
Pleurotus ostreatus, 3.0 and 8.5; and Schizophyllum commune, 
2.8 and 8.5. 
(6) In the peptone solution Schizophyllum commune, Polyporus 
adustus, and Pleurotus ostreatus grow upon a slightly alkaline 
solution, while the other 5 species do not. 
(7) In the peptone-nutrient solution the fungi grow through- 
out a wider range of Ри, have a wider optimum Pg zone, and pro- | = 
duce more felt than on the Richards’ solution. 
