Jan. 17. 1916 
Plenodomus fuscomaculans 
75i 
steamed on three successive days. It was found that steaming instead 
of sterilization under pressure was very important. In a previous 
attempt the media were sterilized in the autoclave, and upon inoculation 
absolutely no growth took place. The experiment was done in quad¬ 
ruplicate with one strain. Inoculation was made with a spore suspension 
as before. The flasks were set in strong diffuse light near a window. 
Readings were made after a month. Five c. c. of water were added to each 
flask, and a second set of readings 1 were made after another month. 
The result of the experiment is shown in Table XXIV. 
Table XXIV .—Effect of quality of food: Test with synthetic solution in various com¬ 
binations 
[Time, 2 months] 
Medium. 
Number of 
pycnidia. 
Growth. 
Potassium acid phosphate, Mjioo 
Sodium carbonate, Mjioo . 
Maltose, Mjioo . 
Magnesium sulphate, M/500. 
>Plus asparagin. .■ 
M/50_ 
Mjioo. . . 
M/500. . . 
Ml 1,000 .. 
Mis f ooo.. 
0 
0 
SO 
0 
O 
+ + 
+ 
+ 
Potassium acid phosphate, Mjioo.' 
Sodium carbonate, Mjioo . 
Magnesium sulphate, M/500. 
Asparagin, M/500. 
-Plus maltose_ 
[Mjio. . .. 
M/so. . . . 
Mjioo. . . 
M/200. . . 
Mj 1,000 .. 
0 
0 
50 
0 
0 
+ + + 
+ + + 
+ ~b 
+ 
4 
Potassium acid phosphate, Mjioo .' 
Sodium carbonate, Mjioo . 
Maltose, Mjioo . 
Asparagin, M/500. 
Plus magnesium 
sulphate. 
M/50. . .. 
Mjioo. . . 
M/soo. . . 
Mji f ooo.. 
Mis,000 .. 
a 13 
1 
So 
0 
0 
+++ 
++ 
++ 
+ 
Potassium acid phosphate, Mjioo.' 
Magnesium sulphate, M/500. 
Maltose, Mjioo . 
Asparagin, M/500. 
Plus sodium car¬ 
bonate. 
Mjio. . . . 
M/50. . . . 
Mjioo. . . 
M/200. . . 
Ml 1,000.. 
0 
0 
50 
* 90 
0 200 
0 
+ 
++ 
++ 
+++ 
Magnesium sulphate, M/500. 1 
Sodium carbonate, Mjioo . 
Maltose, Mjioo . 
Asparagin, M/500. 
Plus potassium 
- acid phosH 
phate. 
Mjio .... 
M/50. . .. 
Mjioo. . . 
M/200. . . 
M/1,000.. 
8 
0 
50 
0 
0 
+ 
++ 
++ 
=t 
0 
a 50 in 1. 
b 29s in 1. 
The device adopted is seen to be a very helpful one in determining the 
value of the various concentrations employed. The cultures in which 
asparagin was varied show how fortunate a concentration was chosen 
in the preliminary experiments. Similarly the experience with maltose 
shows that if asparagin is taken as M/500 then the maltose must have 
1 l am indebted to my colleague, Mr. J. H. Muncie, for making these readings. 
