1921] 
ARMSTRONG—SULPHUR NUTRITION IN THE FUNGI, THIOSULPHATE 273 
actual acidity during much of the growing period was practically 
the same in the two cases cited as for other experiments. 
A separation of free sulphur has occurred, more particularly 
at the higher concentrations. That the deposit is sulphur, or 
Ta 
Ld 
Ped 
— ee 
40 5 
20 6 
0 vd 
Q9 4 8 16 20 
Days 
Fig. 18. Botrytis cinerea on solution of initial Pa 4.1 containing 
magnesium sulphate. 
largely so, is shown by the easy solubility of most of the deposit 
in CS, and by the distinct odor of sulphur obtained on drying and 
heating the deposit. Globules like those in milk of sulphur, a 
well'as many rhombic and monoclinic crystals, were found in the 
cultures with the higher concentrations of the thiosulphate. 
Nathansohn ascribed the separation of sulphur in his cultures to 
the production of a tetrathionate, while Raciborski could find no 
tetrathionate but observed the separation of sulphur. In the 
