Saccharomyces. 



While the true Yeast Fungi grow submerged in the higher layers of 

 the fluid, and there excite active alcoholic fermentation, the " mould" 

 grows on the surface, without exciting fermentation. When artificially 

 forced to grow submerged, of course a little alcohol is produced, but the 

 Fungus soon perishes. 



Although the growth of the layer 

 of " mould " goes hand-in-hand with 

 the souring of the wine or beer, yet 

 the Saccharomyces is not the cause of 

 the latter. The formation of vinegar 

 from alcohol is produced rather by 

 other Fungi, whose systematic position 

 is still undetermined. According to 

 some, it is a species of Vibrio (Spiril- 

 lum) which causes this decomposi- 

 tion. 



89. S. albicans (Robin), 



Reess. 

 Oidium albicans, Robin. 



Cells partly round, partly 

 oval, oblong or cylindrical, 3-5- 

 5 p. thick ; the round ones 4 

 /A in diameter, the cylindrical 

 ones 10 to 20 times as long as 

 thick. Bud-colonies mostly con- 

 sisting of rows of cylindrical 

 cells, from the ends of which 

 spring rows of oval or round 

 cells. Spores formed singly in 

 roundish cells. (Fig. 69.) 



On the mucous membrane 

 of the mouth, especially of in- 

 fants, forming the disease known as aphtha, or thrush. 

 Also in animals. 



This Fungus appears in the form of larger or smaller greyish-white 

 heaps, which nevertheless do not consist exclusively of the Saccharo- 



F 



