1916] 
ZELLER—PHYSIOLOGY OF LENZITES SAEPIARIA 503 
fluence of the resin content of the substratum on the growth 
of the fungus. A resin agar emulsion was prepared, and 
experimental data show that L. saepiaria will grow well on 
50 per cent resin by weight, which is considerably more than 
is found in any coniferous wood. Growth is not entirely in- 
hibited by 85 per cent resin. 
3. The metabolism of the fungus was studied through the 
agency of enzyme action. 
a. A standard method of extracting and isolating the 
enzymes was used, and enzyme preparations were made 
from vegetative and fruiting tissues. The methods com- 
monly used of identifying the enzymes were employed. 
b. Among the esterases, those acting on the esters of 
the lower fatty acids showed more active hydrolysis both 
in sporophoral and mycelial tissues than those acting on 
the neutral fats. 
с. In Ше carbohydrases, positive evidence was ob- 
tained of the presence of maltase, invertase, raffinase, 
emulsin, tannase, diastase, inulinase, ligninase, cellulase, 
hemicellulase, and pectinase, while negative results were 
obtained for the presence of pectase and lactase. 
d. The cyto-hydrolyzing carbohydrases were made a 
special study, together with their effects as demonstrated 
by microchemical observations on sound and decayed 
wood. 
e. The action of amidase on asparagin and acetamid 
was practically negligible, while urease action was very 
decided when the fungous tissue was used instead of the 
enzyme preparations. The presence of hippuricase was 
also demonstrated. 
f. The following additional enzymes have also been 
found: nuclease, proteinases—both tryptic and ereptic— 
rennetase, oxidase, and catalase. 
4. A comparative study of the enzymes occurring in the 
sporophoral and mycelial tissues was made. As we would 
anticipate, this comparison shows that the important metab- 
olic processes are carried on in the vegetative organs. In- 
