1921] 
ARMSTRONG—SULPHUR NUTRITION IN THE FUNGI, THIOSULPHATE 245 
are evident for Botrytis. This organism made fairly good growth 
on the .6 per cent solution of the previous experiment. Since 
no H,S was produced on the 2 per cent thiosulphate solution, an 
attempt was made to account for all the sulphur by titrating for 
the thiosulphate, precipitating the sulphate in solution as BaSQ,, 
TABLE III 
GROWTH AND RELATIONS OF CERTAIN FUNGI ON MEDIA CONTAINING 
SODIUM THIOSULPHATE. TIMEINTERVAL OF CULTURES, 4 WEEKS 
Per cent 
Fungus | No.of |Dry wt. Ce. N/10} NaSO; | H:S | Sul- | Sporu- |Cc. KOH 
cultures | (gms.) | iodine |decomposed phate} lation | N/10 
Experiment 5 —5 per cent Na:80; 
A. nig. 4 .9400 7.6 67.9 2 + 2 1.9 
P. gl. 4 . 2502 18.5 21.9 2 = 4 1.4 
B.cin. None 
Check 1 2076 4 
Experiment 6 —10 per cent Na:8:0; 
A. nig 4 2240 | 29.2 43.7 3 + 1 2.6 
P. gl 4 .2578 45.2 12.9 3 + 3 5 
B. cin. None 
Check 51.9 
Experiment 7 —40 per cent Na:$:0; 
A. nig. None 
P. gl. 4 .5403 | *19.0 7.7 3 7» 0 
B. cin. None 
Check * 20.6 
* One cc. of the nutrient solution was used for a titration because of the high con- 
centration of the thiosulphate. The average of a number of determinations was 
taken. 
and weighing the free sulphur produced as a precipitate in the 
flask, but all such efforts gave low results. Raciborski has re- 
ported the same diffieulty in making quantitative determinations 
of all the sulphur introduced into the nutrient solution. 
The nutrient solution for the experiments in table 111 was of 
