May 16,1921 Glucose as a Source of Carbon for Storage-Rot Fungi 199 
In considering the dry weight of mycelium produced, one must bear 
in mind that the growth of fungi in cultures of the same composition 
varies greatly. The dry weights given in Table V are the averages of 
of the growth from three flasks. It frequently happened during the 
course of these experiments that one culture produced a small amount 
of mycelium when compared with the other two flasks of the same 
series. Had it been possible to obtain the average weight from a large 
number of cultures, the paucity of growth of a single one wou\d not 
have influenced the average so much. 
Kunstmann ( 18) in working with Aspergillus niger and Penicillium 
glaucum on sugar solutions found that in extreme cases there were five 
or more times as much dry material in one culture as in another of the 
same composition and incubated under identical conditions. 
A small amount of mycelium was produced in cultures with no glucose 
added. Diplodia tubericola , Sclerotium bataticola f and Penicillium sp. 
produced considerably more dried material than any of the other organ¬ 
isms, especially at concentrations of approximately 10, 20, and 30 per 
cent; and, as was previously suggested, these were the organisms which 
utilized in general the largest amount of glucose. Sphaeronema fimbri- 
atum , which did not use a determinable amount of sugar, produced a 
smaller amount of mycelium than any other organism. The dry weight 
produced in all of the series is, within the limits of experimental error, 
about equal to the amount produced in the control. 
GLUCOSE REQUIRED TO PRODUCE I GM. OF DRY WEIGHT 
The amount of glucose reduced for each gram of dry weight formed 
is shown in Table VI. It must be remembered that these figures do not 
represent necessarily the quantity of glucose which was actually utilized 
by the fungus in respiration or in producing dry weight, but the amount 
changed so that it no longer possessed polarizing properties. Doubtless 
some of the sugar was consumed in forming various compounds resulting 
from incomplete respiration or other vital activities. 
Table VI .—Grams of glucose reduced for each gram of dry weight formed 
Series 
No. 
Percentage 
of dextrose 
by weight. 
Solution. 
Fusarium 
acumina¬ 
tum. 
Diplodia 
tubericola. 
Rhizopus 
tritici. 
Mu cor 
racemosus. 
T 
fControl. 
1 
0 
( Inoculated. 
O 
r\ 
TT 
IO 
fControl. 
V 
VJ 
( Inoculated. 
* 7 - 5 2 
8. 78 
3 - 70 
19. 65 
TTT 
20 
^Control. 
111 
( Inoculated. 
12. 60 
6- 59 
4 -17 
2 5 - 56 
TAT' 
30 
fControl. 
1 V 
(Inoculated. 
9.07 
4-99 
. 5 -i 7 
28. 88 
40 
fControl. 
V 
(Inoculated. 
6.38 
2. 13 
12. 91 
15.89 
■tTT 
50 
f Control.. 
VI 
(Inoculated. 
17.67 
T A A 
A 7 TT 
fControl. 
1. 44 
Vll 
OO 
(Inoculated. 
