•578 APPENDICES. 



■with the naked eye. II. — Round, oval, and rarely elongated 

 •cells. They produce yeast-turbidity. There are two so-called 

 disease-yeasts allied to this species. The colonies of one kind form 

 .a network. This yeast causes turbidity in beer, and a bitter after- 

 taste. In the other kind the colonies are sharply defined. It 

 produces a disagreeable aromatic taste to beer, and an astringent 

 after-taste. It is widely distributed, and is the principal agent in 

 accidental fermentation. 



Saccharomyces conglomeratus (Reess). — Cells round, 5 to 

 6 ;u, in diam., united in clusters, consisting of numerous cells 

 produced by budding from one or a few mother-cells. There are 

 2 to 4 spores in each mother-cell. They occur on rotting grapes 

 and in wine at the commencem.ent of fermentation. 



Saccharomyces exiguus (Reess). — Conical or top-shaped 

 ■cells, 5 fx, long, and reaching 2'5 /n in thickness, in slightly 

 branching colonies. Spore-forming cells are isolated, each contain- 

 ing 2 or 3 spores in a row. They occur in the after-fermentation 

 of beer ; but, according to Hansen, they do not produce disease 

 in beer. 



Saccharomyces Jorgensenii (Lasche). — Cells small, round 

 or oval. On the surface of wort-gelatine the culture is greyish- 

 white, and the gelatine is slowly liquefied. They ferment saccharose 

 And dextrose, but not maltose. When grown in wort with other 

 yeasts they are rapidly crowded out. 



Saccharomyces pastorianus, I. — Cells oval or club-shaped. 

 Colonies consist of primary club-shaped links, 18 to 22 ;«, long, 

 which build lateral, secondary, round or oval daughter-cells, 5 to 

 6 fji long. Spores 2 to 4. They occur in the after- fermentation 

 •of wine, fruit- wines, or fermenting beer, and in the air of breweries. 

 They produce a bitter taste and unpleasant odour and turbidity 

 in beer. II. — Cells mostly elongated, but also oval or round. 

 ■Cultivated on the surface of gelatine and yeast- water a growth is 

 produced with smooth edges, by which it can be difierentiated 

 from No. III. They occur in the air of breweries, but do not 

 j)roduce disease in beer. III. — They produce yeast- turbidity in 

 beer. On the surface of yeast-water gelatine the cultures, after 

 sixteen days, have hairy edges. 



Saccharomyces apiculatus. — Cells lemon-shaped, both ends 

 bluntly pointed, 6 to 8 ju, long, 2 to 3 /a, wide. Budding occurs only 

 at the pointed ends. Rarely united in colonies. Spores unknown. 

 They occur with other yeasts in various accidental fermentations 

 .and in ripe fruits. 



