1921] 
MATSUMOTO—SPECIALIZATION IN RHIZOCTONIA 13 
temperature of the strains is lower than that of Bl. With 
regard to maximum temperature of those 3 strains named 
above, in most cases no growth is secured at 39-40° C., P4 in 
every case producing no new growth even at 38-39? C. 
Concerning P7, there is no notable difference between 23 and 
33° C., and at 14-16? C. there is still more or less growth. The 
minimum temperature is slightly lower than that of Bl. At 
37-40? C. the growth is much retarded, the maximum being 
somewhat lower than that of Bl. The germination experiments 
show that the growth of P7, though slender, is more vigorous 
in all drop cultures than the remaining strains. 
The growth of the mycelium of B3 on culture media is very 
slow, and at present I find that the strain grows better at a 
lower temperature (about 22? C.) than at a higher (about 35? C.). 
The growth relations of the different strains at certain tem- 
peratures may be illustrated by giving in tabular form the 
results of one of the experiments—in which potato decoction 
was used as a medium. 
TABLE III 
GROWTH jd CERTAIN STRAINS AT DIFFERENT TEMPERATURES, PERIOD 
INCUBATION 3 WEEKS, DRY WEIGHT IN GRAMS 
Strain 38? C. 22? C. Room temperature* 
P1 0.015 0.345 0.045 
P4 Negl 0.185 0.100 
p 0.015 0.120 0.010 
B1 0.270 0.120 0.005 
H 0.020 0.300 0.050 
* This was 14-17? C. at night and 17-20? C. during the day. 
Such relations resulting from other experiments are also shown 
graphically by fig. 4. In general, the growth during the first 
2 days is very slight, so that in the figure there is given an aver- 
age of the observations taken during the first 5 days. 
NUTRITIVE METABOLISM WITH SPECIAL REFERENCE TO ENZY- 
MATIC ACTIVITIES 
In general, the species of fungi exhibit a more or less marked 
specialization both qualitatively and quantitatively in respect 
