ALCOHOLIC FERMENTS. 217 



SACCHAROMYCES ANOMALUS (HANSEN). (Figs. 42 and 68.) 



This very curious species was found by HANSEN in an 

 impure brewery yeast from Bavaria. It gives a rapid and 

 vigorous fermentation in wort, and even at the beginning of 

 the fermentation develops a dull grey film. During fermen- 

 tation the liquid acquires an ethereal, fruity odour. 



The cells grown in wort are small, oval, or sometimes 

 sausage-shaped, and in their microscopic appearance they 

 resemble the Torula species. When the development has 

 gone on for some time' many cells both in the sediment and 

 in the film are found to contain spores. 



Fid. 08. Saccharomyces anomalus in sporulation. Some spores are free, others 

 inclosed in the mother-cells. On the right-hand side three spores are surrounded by 

 the burst wall of the mother-cell (after HANSEN). 



Spores are developed on various substrata, both liquid and 

 solid, even under conditions where abundant nutriment is 

 present. 



The form of the spores is highly characteristic (Fig. 68); 

 it resembles a hemisphere with a projecting rim round the 

 base. On germination the spores swell and develop buds 

 (see Fig. 42). 



The maximum temperature for spore- formation is 32-32 J C., 

 the minimum temperature 3-6 C., the optimum lying between 

 28 and 31 C. (17 J- 19 hours). (NIELSEN.) 



After HANSEN had drawn attention to this curious Sac- 

 charomyces species, it was observed, together with other allied 

 species, by HOLM, LINDNER, and WILL, who also found it in 

 impure brewery yeast. Yeasts yielding hat-shaped spores 

 appear in fact to be by no means uncommon. 



In English high-fermentation beers, which were " fretty," 

 the author observed a species belonging to this group, which 

 was multiplying very freely, so that all other yeast-cells had 



