126 



BACTERIA 



SaccJiaromyces Cerevisice. Oval or ellipsoidal cells ; repro- 

 duction by budding; ascospores, rapidly at 30 C., slowly 

 at 12 C., not formed at all at lower temperatures; film 

 formation, seven to ten days at 22 C. ; an active alcoholic 

 ferment, producing in a fortnight in beer wort from 4 to 6 

 per cent, by volume of alcohol (Jorgensen). This species 

 is a typical English " high" yeast, possessing the power 

 of " inverting " cane-sugar previous to producing alco- 

 hol and carbonic acid. It is said to have no action on 

 milk-sugar. 



Saccharomyces Ellipsoideus L Round, oval, or sausage- 

 shaped cells, single or in chains ; ascospores in twenty-four 



>/'/ 



S. ELLIPSOIDEUS 



S. PASTORIANUS 



hours at 25 C. (not above 30 C., not below 4 C.). Grown 

 on the surface of wort-gelatine, a network is produced by 

 which they can be recognised (in eight to twelve days at 

 33 C.). At 13-15 C. a characteristic branching mass is 

 produced. It is an alcoholic ferment as active as 5. cere- 

 visice. S. Ellipsoideus II. Round and oval, rarely elong- 

 ated, a widely distributed yeast, causing " muddiness " in 

 beer and a bitter taste. It is essentially a " low " yeast. 



Saccharomyces Conglomeratus is a round cell, often united 

 in clusters, and occurring in rotting grapes, and at the com- 

 mencement of fermentation. 



