1921] 
MATSUMOTO—SPECIALIZATION IN RHIZOCTONIA 25 
any condition studied maltase is formed at least in small quan- 
tities. 
In dealing with lactase the same procedure was carried out 
as for maltase, except that lactose was used as a substrate. 
Three experiments with the use of mycelial extractions obtained 
from mats of the fungi grown on potato decoction were made 
at different periods, but there is no distinct indication of the 
presence of the enzyme in an extract from any strain. Never- 
theless, the secretion of a lactase by these fungi is suspected 
because of the constant utilization of lactose when the strains 
are cultured on that medium. In the hope of securing more 
definite results in this direction further experiments were made 
with the 6 strains as shown in table xim. 
TABLE XIII 
GROWTH OF THE 6 plana ale ON MALTOSE AND LACTOSE MEDIA AFTER 4 
WEEKS, DRY WEIGHT IN GRAMS 
Media P1 P4 P7 B1 H B3 
Maltose 0.870 0.850 0.670 0.870 0.790 Negl. 
Lactose 0.400 0.280 0.640 0.710 0.317 Negl. 
From this experiment it appeared that all the strains were 
able to utilize lactose as a source of carbon, although its avail- 
ability was much less than that of maltose. 
In dealing with lactose the same procedure as described 
above for maltase was carried out, except that the extracts were 
added to 2 per cent lactose solutions and incubated for 1 month. 
Four determinations were made. The results were rather vari- 
able, the quantity of K,MNO, required for 2 cc. of the solution 
varying from 3.2 to 4.1 cc., the experiments indicating that all 
the strains may contain a small amount of lactase but of low 
activity. 
Monosaccharides.—For these tests 2 per cent glucose, fructose, 
and galactose dissolved in the stock solution were used, with the 
conditions as in the previous experiments. 
From table xiv it is inferred that all the monosaccharides 
are directly utilized by the fungi, with approximately equal 
