236 



FAMILY OF SACCHAROMYCETACEAE 



Fig. 103. S. monacensis. 



I. Vegetation of a Culture on Beer Wort after 2 to 3 Days at 

 32-33C. 2. Giant Cells Obtained in a Culture of 10 Days 

 in Yeast Water to Which Dextrose Was Added at 9 C. 

 3. Vegetation after 16 Days on Beer Wort at 1-2 C. (after 

 Hansen). 



At the maximum temperature, this yeast has ellipsoidal cells predomi- 

 nating with a few in the form of chains. The cells are larger and 

 longer (Fig. 103, 1); at the minimum temperature, spherical and 

 ellipsoidal cells may be seen at the end of 18 days. At the end of a 



month, one may find 

 ^^ 



small number of colonies 

 composed of cells in a 

 short chain with a few 

 rare giant cells. (Fig. 

 103, 3.) 



In yeast water to which 

 dextrose has been added, 

 one may notice after about 

 12 days at 9 C. a feeble 

 formation of a mycelium. 

 On the other hand, in 

 this medium giant cells are so numerous and so large that they serve 

 as a distinguishing characteristic between this species and the preced- 

 ing one. (Fig. 103, 2.) 



At 13 to 15 C., one may see at the end of about a month in a 

 Pasteur flask, the beginning of a scum with the form of floating islands 

 in which the cells are spherical or ellipsoidal. At the end of a year, 

 one may see in cultures, maintained at labora- 

 torjr temperatures, an abundant scum formation 

 which generally covers about all of the surface. 

 These scums are again composed of cells which 

 are ellipsoidal or round, chain formation being 

 extremely rare. 



Ascospore formation is accomplished more 

 easily in this species than in the preceding one, 

 without being abundant. (Fig. 104.) But it is impossible to deter- 

 mine the temperature limits of this formation. 



Giant colonies on wort gelatin have much the appearance of 

 those of the preceding species. They take the shape of rosettes with 

 an undulating border. The colonies have a depressed center which is 

 surrounded by a more elevated ring than with S. carlsbergensis. How- 

 ever the center of the colony consists more often of a wart and the 

 points of the rosette are a little more pronounced than in S. carls- 

 bergensis. S. monacensis is a yeast producing a typical bottom fermen- 

 tation, fermenting dextrose, saccharose, maltose and not lactose. 



Fig. 104. S. monacen- 

 sis, with Ascs (after 

 Hansen) . 



