222 Barker. — A Fragrant 'Mycoderma' Yeast , 
about forty-eight hours after infection at 28° C. When fully 
developed it has a greyish-white colour, is very thin, and has 
a powdery appearance. It is not wrinkled, but resembles 
early stages in the development of the films on beer-wort 
and dextrose-Mayer. 
On dextrin-Mayer solution after twenty-four hours at 25° C. 
the film begins to be visible. Twenty-four hours later it is 
thick, much wrinkled and of a grey colour, being identical 
in appearance with the films on beer-wort. It gradually 
breaks up and eventually disappears altogether. 
On soluble starch in Mayer’s solution a thin white powdery- 
looking film is formed in about seven to ten days at 28° C. 
The film is not usually well developed on the liquid, but 
spreads vigorously over the surface of the flask in a some¬ 
what mycelium-like manner. 
On examination under the microscope, the primary films 
are seen to be made up of Yeast-cells, actively budding, 
enclosing in the spaces between the cells numerous gas- 
bubbles. These bubbles adhere very tenaciously to the cells, 
and appear to be concerned in preventing the wetting and 
sinking of the film in water. 
Secondary films are formed by this Yeast on those solutions 
in which it is capable of inducing alcoholic fermentation, viz. 
on beer-wort, dextrose, laevulose and saccharose-solutions. 
They begin to make their appearance some time after active 
fermentation has ceased, and after the primary film has dis¬ 
appeared. On cultures two months old the film can be 
observed as a thin fatty-looking layer over the surface of the 
liquid. It is semi-transparent and greyish in colour, and 
resembles somewhat in appearance the bloom seen on certain 
fruits, such as plums or grapes. The appearance of the film 
is the same on either beer-wort dextrose, laevulose or sac¬ 
charose solutions. The films are formed both at room-tem¬ 
peratures and also at 25~30°C. 
Under the microscope, numerous gas-bubbles are seen to 
be included among the Yeast-cells. Most of the cells are 
round or slightly oval with sharply-marked cell walls, one or 
