1921] 
WEBB—GERMINATION OF SPORES OF CERTAIN FUNGI 295 
constituted a series. Certain definite Py values regarded as 
important for this study, as well as for other physiological studies 
of the fungi, were desired for each medium, for instance, Py 3.0, 
the optimum concentration for germination of certain forms in 
mannite, as shown by previous studies; several concentrations 
greater than Pg 3.0, in order to determine inhibiting concentra- 
tions; Py 6.5 for the influence of slight acidity; Px 7.0 for neu- 
trality; and Py 7.5 for slight alkalinity. Aside from these de- 
sired concentrations the range Pg 1.2-10.04- has been con- 
veniently but not equally subdivided. 
Similar technique to that described in my previous paper 
(Webb, 19) was used throughout this study. For any organism, 
and usually for several organisms, a stock solution of a specific 
medium was made up at one time, so that all data in this paper 
represent uniformity for an organism and a particular medium. 
The initial Py of any stock solution varied somewhat, varia- 
tions of several tenths not being infrequent despite the most 
careful technique during the preparation and the use of highest 
purity chemicals. Since the highest purity monobasic potassium 
phosphate then obtainable exhibited a high acidity, the salt was 
recrystallized until the Sörensen coefficient of Py 4.529 for 1/15 
molecular was obtained. 
Doubly distilled water testing Py 5.2-5.4, distilled first from 
a Bourdillon still with a block tin condenser, and then redistilled 
in Pyrex flasks containing several crystals of KMNO, and 
condensed in the usual glass condenser, has been used in all of 
the experiments here reported. 
METHOD OF CULTURE 
The methods employed, essentially those described by Clark 
(99) and Duggar (’01), are substantially those used in my 
previous work (Webb, '19) and need not be described again. 
All cultures were run in duplicate and a series with every organism 
was incubated at three different temperatures, a range of 4-5° C. 
on either side of an approximate optimum temperature being 
sufficient for all purposes. 
The spores of C. Gossypii, it was found, germinate with diffi- 
culty in hanging-drop cultures, but germinate more readily in 
