WOLPERT—FUNGI AND H-ION CONCENTRATION OF MEDIA 81 
4. This criterion is used throughout the series where celluloses 
are used in liquid cultures. 
The hydrolysis of the filter-paper is also measured according 
to a definite scale ranging from 0 to 6, where 0 represents no utili- 
zation as evidenced by the intact strips; 1, strips appear intact 
but are rather easily shredded upon being touched; 2, more than 
75 per cent of the strips are intact, but 25 per cent are already 
partially decomposed and shredded; 3, more than 50 per cent 
and less than 75 per cent of the strips are intact; 4, more than 25 
per cent but less than 50 per cent of the strips are intact and less 
than 25 per cent completely shredded; 5, less than 25 per cent 
of the strips are intact, but more than 25 per cent and less than 
50 per cent are completely decomposed; and 6, the strips are 
entirely decomposed into a fibrous condition. 
Table хіп shows that all the fungi are able to some extent to 
utilize filter-paper as a source of carbon. Some species, such as 
Armillaria mellea and Polystictus versicolor, throughout the entire 
Pa range from 3.0 to 7.0, show considerable hydrolysis of the 
paper, more than half of the strips being dissolved and partially 
utilized. Other forms, such as Daedalea confragosa, Pleurotus 
ostreatus, and Polyporus adustus, show less utilization of the paper 
cellulose. Lenzites sepiaria, Schizophyllum commune, and Pholiota 
adiposa make minimum use of this source of carbon. In only one 
ease, Pholiota adiposa at Pg 5.0, is over 50 per cent of the cellulose 
dissolved, while with the other 2 species, Lenzites sepiaria and 
Schizophyllum commune, more than 75 per cent of the strips are 
left intact or are only slightly shredded after 30 days. Schizo- 
phyllum commune, Daedalea confragosa, and Pleurotus ostreatus 
do not grow at Ри 3.0, while all of the other species are eapable 
of a small amount of growth at this acidity. Polyporus adustus, 
Daedalea confragosa, Pleurotus ostreatus, апа” Armillaria mellea 
grow as well at Pa 7.0 as at any other Py, while the other species 
are characterized by maximum mycelial growth and utilization 
of the filter-paper at the intermediate reactions. 
Although there is some considerable variation in Pg, all species 
except Polystictus versicolor reduce the active acidity of the more 
acid solutions. Daedalea confragosa, Armillaria mellea, Schizo- 
phyllum commune, and Polyporus adustus slightly increase the 
