620 
Journal of Agricultural Research 
Vol. XXI, No. 9 
The quantity of sand used for grinding the mycelium does not influence 
the rate of maceration, as is shown by the results of comparative experi¬ 
ments in which several uniform lots of mycelium were ground with 0.25, 
0.5, 1.0, 5.0, and 10.0 gm. of sand, respectively, and transferred to small 
Erlenmeyer flasks. To each flask were added 25 ce. of distilled water 
and immediately the usual sized sweet-potato disks. Maceration carried 
out at 37.5 0 C. was complete in all samples ground in sand in 3.5 hours. 
In the unground samples which served as controls maceration was com¬ 
plete in 4 hours. 
Toluol as an antiseptic. —In experiments where a considerable 
length of time was required to complete maceration, about 2.5 cc. of 
toluol, or enough to cover the surface of the liquid, was used as an anti¬ 
septic. Usually antiseptics were not employed, since maceration was 
completed before foreign organisms became sufficiently abundant to 
influence the results materially. Sweet-potato disks immersed in pure 
toluol for 19 hours showed no evidence of maceration. The use of toluol 
as an antiseptic in flasks containing enzym powder did not retard the 
maceration of sweet-potato disks when compared with flasks to which no 
toluol was added, maceration being completed in each case in an equal 
length of time. 
Extraction op the hyphaE. —The usual method in investigations 
of this kind is to extract the powdered mycelium with water for a given 
time, filter off the solid matter, and subject the disks or material to be 
macerated to the extract. Two objections may be offered to this method. 
First, it requires a considerably longer time to carry out the experiments 
and, second, all of the enzym may not be removed from the liyphae. 
A considerable number of experiments which need not be related in all 
their details were conducted to determine whether extraction of the 
hyphae was necessary or desirable. A comparative study was made of 
the rate of maceration of 0.25 gm. of hyphae extracted for 18 hours in 
25 cc. of water at 9 0 and at 37.5 0 C., respectively, and of hyphae not 
previously extracted. The results of these experiments showed that the 
disks added to the unfiltered solutions and incubated at 37.5 0 in both 
the extracted and nonextracted mycelium were macerated in the same 
length of time. 
Filtering. —Since extraction of the mycelium was found unnecessary, 
filtering the solutions free of the mycelial particles and sand was not 
practiced. Suffice it to say in this connection that the several experi¬ 
ments conducted showed that filtering the solution through one and two 
thicknesses of No. 2 Whatman chemically prepared filter paper consider¬ 
ably weakened the extract. To just what the weakening of the enzym 
was due was not determined, but it is probable that some of the enzym 
was retained in and adhering to the fungous particles and sand which 
were caught by the filter paper. 
