[Vor. 8 
244 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
4.0 cc.; (NH,),HPO, M/6, 27.7 cc.; KH,PO, M/6, 2.2 cc.; 
MgCl, M/1, 1.0 cc.; CaCO, M/100, .5 ec.; FeCl, M/1000, .5 cc.; 
sucrose M/1, 7.3 ec. The length of the experiment was 4 weeks 
for number 3 and 5 weeks for number 4. 
TABLE II 
GROWTH AND —— OF CERTAIN FUNGI ON MEDIA CONTAINING 
ODIUM THIOSULPHATE 
Experiment 3 Experiment 4 
.6 per cent Na:S:0; 2 per cent Na.S.0; 
Fungus A. nig. | P. gl. | B. cin. | Check | A. nig. | P. gl. | B. cin. |Check 
No. cultures 5 5 6 1 4 4 1 
Dry wt. anh ) | .0448 | .4046 | .2509 .4152 | .6164 | none 
Ce. N/10 0 1.9 .9 3.0 2.1 3.8 8.0 
% NAT 
decomposed 100 36.6 | 70.0 73.7 | 52 
2 — — — — 0 0 0 
Sulphates + + + -+ d — 
Sporulation 1 3 
On the solution employed in experiment 3 Aspergillus made 
very little growth, yet all the thiosulphate had disappeared from 
the solution. The sulphates determined as BaSO, were so low 
that other tests were tried to discover the changes which had pro- 
ceeded, and these seem to indicate the production of a tetrathio- 
nate. The tests were made as follows: To the solution in which 
there was no thiosulphate, BaCl, was added and the sulphate 
formed was caught in a Gooch crucible. The filtrate was oxi- 
dized with bromine and BaCl, again added. A second white 
precipitate was formed which indicates the production of a 
polythionate. Qualitative tests with mercurous nitrate gave a 
yellow precipitate which might be produced by either the tetra- or 
pentathionate. Potassium hydroxide added to the solution gave 
no precipitate of sulphur which should be the case if the pentathi- 
onate were present. Hence, it appears that the tetrathionate 
was in the solution. 
In the 2 per cent concentration of thiosulphate in the solution 
as employed in experiment 4, the toxic effects of the thiosulphate 
