230 Barker.—A Fragrant 'Mycoderma' Yeast , 
starch, dextrose, saccharose, and laevulose. The solutions 
of each used, with the exception of soluble starch and laevulose, 
were 10 per cent, of the substance, made up with Yeast 
extract. Also with the exception of the first three substances 
mentioned, solutions of 15 per cent, of the carbohydrate 
made up with Mayer’s solution were made, the constitution 
of each thus being:— 
15 grams carbohydrate. 
1 gram ammonium tartrate. 
•5 „ potassium phosphate. 
•25 „ magnesium sulphate. 
•05 „ calcium phosphate. 
100 c.c. distilled water. 
The action of the Yeast on beer-wort was also determined. 
The results showed that it can ferment saccharose (presumably 
after inverting it), dextrose, laevulose, and beer-wort, but 
cannot ferment xylose, dextrine, acacia gum, mannite, lactose, 
or soluble starch. 
With reference to the fermentation of maltose, a few small 
gas-bubbles are found at the edges of the liquid, when film- 
formation has taken place. They are not numerous and 
may be due merely to air enclosed by the film during its 
formation. If they are due to fermentation, then the fer¬ 
mentation that takes place is very feeble. 
A film is formed on each of the above solutions, but in 
the cases of xylose, gum acacia, and mannite, the growth 
observed may have been due to the presence of Yeast extract 
and not to the carbohydrate. 
In all the other cases, however, growth was due to the 
carbohydrate, since cultivations on the substance dissolved 
in Mayer’s solution produced films as well as those on the 
substance made up with Yeast extract. 
Fermentation is of a vigorous character with each of the 
substances that the Yeast is able to ferment, that of beer- 
wort, however, not being as vigorous as the others. It started 
in from two to three days after infection at 28° C. and con- 
