Saccharomyces anomalus (Hansen). 
221 
Films. 
Primary films 1 are formed by this Yeast on the surface of 
every culture-solution in which it is able to grow. They 
differ in character and in rate of growth according to the con¬ 
stitution of the culture-solution. 
On beer-wort in most cases the film begins to form in 
twenty-four to forty-eight hours at 28° C. and twenty-four hours 
later appears as a thick greyish-white, dry and powdery, greasy 
looking, much wrinkled film. Fermentation then proceeds 
actively, and the film is to a great extent broken up by the 
bubbles of carbon dioxide evolved. When active fermen¬ 
tation ceases the film re-forms, but not so strongly as before, 
and after a time disappears and is replaced by the secondary 
film. In a few cases no continuous film was formed until 
fermentation ceased. At 18 0 C. the formation of the film took 
place more slowly. 
On dextrose-Mayer solution a film is produced similar to 
that on beer-wort. It is however better-developed, more 
wrinkled and of a whiter colour. Formation begins in twenty- 
four to forty-eight hours at 28° C. Its fate is similar to 
that on beer-wort. 
On saccharose-Mayer and laevulose-Mayer solutions the 
films are like those on dextrose-Mayer. On lactose-Mayer 
solution the first signs of film formation appear in about 
forty-eight hours after infection at 28° C. In its early stages 
it looks like a few patches of fatty matter lying on the surface 
of the liquid. These patches increase in size and eventually 
fuse together, forming a complete film over the surface in 
five days after infection at the above temperature. It is very 
thin and somewhat fatty-looking, and is also semi-transparent. 
It gradually breaks up and disappears. 
On maltose-Mayer solution a film begins to develop in 
1 By primary film is meant the film which forms before fermentation, as distinct 
from the veils (secondary films), which Hansen found were developed by many 
Yeasts after the culture has stood for some time. (See 4 Jorgensen, Mikroorganis- 
men der Gahrungsindustrie/ 4th ed., 1898, p. 173.) 
