2i6 Barker.—A Fragrant ‘ Mycoderma' Yeast , 
and manner of growth seemed to be a form of so-called 
Mycoderma , with considerable resemblances in external 
characters to the ordinary M. cerevisiae and M. vini , but 
closer investigations showed that it is a very different 
organism. 
Pure cultures were obtained by the following method :— 
a portion of the film was shaken up vigorously in a test-tube 
of sterile distilled water, and a drop of this liquid then poured 
into a test-tube of beer-wort gelatine 1 . From this a fractional 
series of six plate-cultures of beer-wort gelatine was made 
and allowed to grow. Then a second series, infected from 
a colony growing on a plate of the first series, was made, 
to ensure the purity of the culture. 
A stock of the organism was obtained by making a streak- 
culture on a tube of beer-wort gelatine from a colony 
developed on a plate of the second series. In order to prevent 
contamination of the stock, a new stock-tube of beer-wort 
gelatine was always infected whenever the original stock-tube 
was opened to obtain a supply of the organism, and the new 
stock used for the next supply. Occasionally a new series 
of plates was made, infected from the stock-tube in order 
to check the results, and to ensure that the organism con¬ 
formed to type, and a new stock made from a single colony 
on one of the plates. 
Morphology. 
In general culture on beer-wort, dextrose-Mayer solution, 
or other nutrient solutions 2 , this Yeast forms, as a rule, 
a greyish-white film on the surface of the liquid. It has 
a very floury or powdery appearance, as if composed 
of innumerable greasy particles; and if the growth is very 
vigorous, the film becomes much wrinkled by mutual 
crowding of its units. Most of the cultures were made in 
Erlenmeyer flasks, and the Yeast had a curious habit of 
growing over the surface of the glass above the liquid up 
1 Unhopped Beer-wort 90 c.c. Gelatine 10 grams. 
2 See p. 230 for the constitution of these solutions. 
