CLASSIFICATION OF THE YEASTS 195 



Genus IX. Saccharomyces. Meyen 



Ascospores in a single membrane, germinating by budding some- 

 times with the formation of a rudimentary mycelium. 



First Sub-Group: Saccharomyces fermenting dextrose, maltose 

 and saccharose, but not lactose. 



Second Sub-Group: Saccharomyces fermenting dextrose and sac- 

 charose but neither maltose nor lactose. 



Third Sub-Group: Saccharomyces fermenting dextrose and mal- 

 tose but neither saccharose nor lactose. 



Fourth Sub-Group : Saccharomyces fermenting dextrose but not 

 maltose, saccharose nor lactose. 



Fifth Sub-Group: Saccharomyces fermenting lactose. 



Sixth Sub-Group: Saccharomyces not inducing fermentations or in 

 which the characteristics of fermentations are insufficiently known. 



Genus X. Hansenia. Lindner. Klocker 

 Apiculate cells. Ascs with a single ascospore. 



FOURTH GROUP 



Budding yeasts which form a scum immediately in sugar media; 

 scum is dry and opaque, including air. Ascospores in characteristic 

 shapes (in the form of a lemon, hat or angulous) with a single mem- 

 brane, often with a projecting collar. Generally do not produce 

 alcohol but ether. 



Genus XL Pichia. Hansen 



Hemispherical ascospores. Rudimentary mycelium well developed. 

 Do not cause fermentations. 



Genus XII. Willia. Hansen 



Ascospores in the form of a lemon or hat with a projection like 

 a girdle; generally do not produce alcohol but ether. 



FIFTH GROUP 

 Yeasts in which the relationships are not well known. 



Genus XIII. Monospora. Metschnikoff 



Budding yeasts, ascs with a single ascospore, in the form of a 

 needle, germinating laterally by budding. 



