[Vor. 8 
296 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
thin films placed on slides. "The slides bearing the spore suspen- 
sion were elevated upon corks in large Petri dishes, and relatively 
large quantities of the solution to be tested were placed in the 
bottom of the dishes. The cultures being destroyed upon 
examination, it was possible to make only one reading. 
In testing the change in reaction of the medium during ger- 
mination, 2-ce. portions of the various solutions of a series were 
placed under aseptic conditions in sterile test-tubes. The tubes 
had a volume of 22 cc. and were plugged with cotton. Several 
loops of spores were placed in each test-tube of solution, care 
being exercised to secure a heavy and uniform suspension, and, 
following inoculation, the cultures were allowed to incubate at 
a provisional optimum temperature for a period of 20 hours. 
All of the cultures were set up in duplicate and controls were 
run simultaneously. The initial and final hydrogen-ion concen- 
trations were determined in the usual way. 
Extreme precautions were exercised in the care and the clean- 
ing of glassware. A detailed description of such operations may 
be found in the writer’s earlier paper (Webb, ’19). 
EXPERIMENTAL DATA 
Cultures were examined at different intervals, depending on 
An. 
Pereentoge of Germination 
M 
; 
FI e] 
wN. “4 
in 
: Fa 
Vy: c 
4 
Vii 
75 
rs 
| | 
Fy 
GAA 
BS 
M H PW 
l ‘N 
| S 
^ 
n" / N he) 
«o Jil XY a 
N 
/ NIY 
1 wA 
^, 4 2 3 4 C 6 7 a 9 JI 
Fig. 2. Botrytis cinerea in M/5 mannite solution. 
the length of time required for the spores of the particular fungus 
to germinate, as determined from preliminary experiments. 
Spore counts were made from 5 different fields of the hanging 
