1921] 
WEBB—GERMINATION OF SPORES OF CERTAIN FUNGI 293 
Beet Decoction.—The sugar beet decoction was prepared accord- 
ing to the method outlined by Duggar, Severy, and Schmitz 
(17). This consists essentially of 370.4 gms. of sugar beets per 
liter of distilled water, autoclaved at 15 pounds for 1 hour and 
then filtered. Karrer and Webb's (720) titration curve and 
method of varying the hydrogen-ion concentration have been 
used as a basis, and the detailed remarks for Czapek’s full 
nutrient solution adequately suffice in this case. The beet 
decoction was made in concentrated form and in sufficient 
quantity for all of the experiments here reported during the late 
summer of 1920. This decoction, with proper dilution and 
without addition of either acid or alkali, tested Py 5.2, and the 
H-ion concentration was varied on either side by regulated 
amounts of N/5 HCl and N/5 KOH. The buffer action on the 
alkaline side is extremely weak, in fact, much weaker than that 
of bacto-peptone. Without doubt N/20 alkali would have been 
better than N/5 for the adjustment of reactions in this medium. 
The stock solutions of beet decoction, however, were made be- 
fore this point was determined, and it seemed unwise to change 
the plan at this stage. No noticeable precipitate immediately 
occurred in the alkaline cultures, although precipitation did 
occur upon prolonged standing, and a decided color change 
from pale yellow to amber was noted as the reaction passed 
from acid to alkaline. 
Water.—Distilled water was adjusted to different hydrogen- 
ion concentrations by two methods: (1) by successively increas- 
ing additions of N/5 NaOH to equal quantities of M/10 H;PO,, 
(2) by additions of acid or alkali to distilled water. The ad- 
justments in the first case were arranged on the principle de- 
scribed for the mannite culture solutions and the term '* water 
H,PO, and NaOH" has been applied to water so regulated. 
In the other case distilled water was brought to the required Pa 
value by means of N/5 HCl or N/20 KOH and the term “water 
HCl or KOH" has been employed to designate these solutions. 
Distilled water testing Py 5.2-5.4 was the best that could be 
obtained. The titration curve, as presented, was worked out 
very hastily and no special precautions have been taken. Despite 
the fact that it may be subject to some criticism, it is included 
