[Vor. 11 
52 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
In the agar series each 1000 cc. of medium contained 500 се. 
of the cellulose suspension, 500 cc. of the nutrient salt solution, 
and 20 gms. of agar. The Pa was adjusted by the addition of M/3 
solutions of Н.РО, and KOH. То 150-се. amounts of the warm 
agar mixture were added: 
Series 1, 5.0 ec. H;PO,, giving approximately Pa 2.8. 
Series 11, no addition, giving approximately Pg 4.0. 
Series ш, 2.5 се. KOH, giving approximately Рн 4.6. 
Series ту, 3.5 cc. KOH, giving approximately Ру 5.0. 
Series v, 5.0 сс. KOH, giving approximately Рн 6.0. 
The sterile acid and alkali were added aseptically. After thor- 
oughly mixing to assure uniform distribution, the solutions were 
poured into sterile plates, cooled, and inoculated 
Glassware.—All the glassware was scrubbed with cleaning 
powder, cleaned in a strong cleaning solution recommended by - 
Duggar (709, page 13), rinsed in tap water, rinsed in distilled 
water, and drained dry. Proper precautions were taken to 
protect such cleaned glass from dust. Pipettes or other glass- 
ware for use under sterile conditions were dry-sterilized for at 
least 1 hour at 150-170? C. 
Methods and examination of cultures.—Using all precautions 
against contamination, triplicate cultures were made іп 120-се. 
Erhlenmeyer flasks, each one containing 35 сс. of solution. 
With the exception of the nutrient-agar-cellulose series, which 
were incubated at room temperature, and of the cellulose and 
peptone series without sugar, which were incubated only at 
25% C., all cultures were incubated for 30 days at 15? C., 25° C., 
and 85° C. Тһе lowest temperature was maintained approxi- 
mately between 14? C. and 18? C. in a cellar, while the other 2 
tely by means of thermostats in incubators. 
In all cases where possible, examination was made upon the 
final Ри of the solution and upon the dry weight of the fungus. 
This weight was obtained by drying the green mat upon pre- 
viously dried and weighed filter-papers for 2 days at 100-105" - E 
C., and by weighing the combined mat and paper. Тһе differ- 
ence between the weight of the paper and that of the mat and 
paper is the weight of the mat alone. Тһе triplicate figures 
obtained were averaged and given as one reading. 
