[Vor. 11 
50 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
give a total of 9.65 gms. of phosphates; and doubly distilled water 
to make 1000 ec. of solution. This peptone-nutrient solution 
throughout this work will be referred to as the peptone solution. 
This solution without sugar gave the third type of media used 
in this first elass of solutions. As with the Richards' solution, 
slight variations in the hydrogen-ion concentrations were encount- 
ered, but these were all eliminated by slight modifications of the 
phosphate content, indicated in table rr. 
TABLE II 
THE Segre OF THE PEPTONE-NUTRIENT SOLUTION paio TO 
RANGE OF Pg FROM 2.0 TO 8.5 AT INTERVALS OF 
Initial No. ec. No. ec. No. се. No. cc. Total 
Ps M/3 H;PO, M/3 KH;PO, |M/3 Ka3HPO,| nutrient | по. cc. 
solution 
2.0 7.0 1 ec. conc. H;PO, 28 35 
2.5 7.0 0.1 ec. conc. H;PO, 28 35 
3.0 7.0 28 35 
3.5 5.0 2.0 28 35 
3.9 3.0 4.0 28 35 
4.5 2.0 5.0 28 85 
5.0 1.0 6.0 28 35 
5.6 : 7.0 28 35 
6.0 6.0 1.0 28 35 
6.5 4.5 2:6 28 35 
7.0 2.0 5.0 28 935 
7.4 1:0 28 85 
7.8-8.2 |0.5 gm. СаСО; 7.0 28 85 
8.5-8.7 |1.5gm.CaCO; 7.0 28 35 
0.2 cc. conc. 
The nutrient solution was made up and added to the culture 
flasks in the same manner as in the Richards’ solution. Неге, 
too, the Н,РО, and K.HPO, were added aseptically. 
The second group of nutrient solutions, those containing 
celluloses as the only or chief source of carbon are: (1) a modified 
Richards’ E solution with a wood cellulose suspension substi- 
tuted for the cane sugar; (2) a 0.5 per cent peptone-nutrient 
solution to which is added 20 gms. of filter-paper in strips for 
each liter of medium; and (3) the Richards’ solution modified 
as in (1) with the addition of 20 gms. of agar 
The celluloses were prepared from bunt. Dine; white oak, 
sugar maple, and poplar woods. Two-hundred-gm. amounts of | 
each wood cut into small chips were treated for one month at | 
