FERMENTATION. Ill 



elements. The spore-forming cells are larger 7-8. 5/j, and 

 contain from 2-4 spores 3.5/n in diameter. He ascribes to 

 this ferment the action of fermentation in bread, a notion 

 that has since been scouted and again accepted. 



12. Saccharomyces conglomeratus (Reess), Hansen thinks 

 is simply a form that may be met with in old films of all- the 

 six species that he specially investigated, and in recent works 

 this species has been dropped. 



13. Saccharomyces aptculatus, described by Reess, can 

 scarcely be said to be a true saccharomyces, although 

 it is included amongst them by Zopf as a doubtfiil 

 member of the group ; it has not yet been ascertained 

 to have any spore formation, and is therefore retained by 

 Hansen in this group only provisionally. It occurs in fer- 

 mented wine and spontaneously fermented beer, and, in the 

 hot seasons, on sweet succulent fruits, such as cherries, goose- 

 berries, plums, or grapes ; whilst in the winter it is found in 

 the soil beneath the trees that bear these summer fruits. It 

 occurs in cultivation fluids as lemon-shaped cells — ^hence the 

 name — though under certain conditions it assumes elongated, 

 crescent-shaped, and rod-shaped forms. It gives off buds of 

 two kinds : one oval, the other lemon-shaped. It is a bottom 

 yeast giving rise to a feeble alcoholic fermentation ; it does 

 not invert cane sugar, but acts on dextrose in yeast water, 

 but does not ferment it completely. Mixed with Saccharo- 

 myces cerivisiae it retards the action of the latter. 



An organism that was long classified with the true yeasts 

 is the Rosahefe or Pink yeast of the Germans. Accord- 

 ing to Hansen, however, no spores are formed during any 

 phase of its development and for the present he excludes it 

 from the Saccharomyces or true yeasts. It belongs rather to 

 the Torulae. 



Genus II. (i) Monospora (MetschnikoflF). The single mem- 

 ber of this group, Monospora cusptdata, is of interest princi- 

 pally because of the elaborate researches that have been made 

 by Metschnikoif on its relation to a pecuhar disease of the 

 Daphnia, a small fresh-water crustacean. It occurs as a bud- 

 ding mycelial thread made up of elongated cells which before 

 spore formation become elongated ; there then appears a long, 

 thin needle-like body situated in the centre of the cell in its 

 long axis. This spore is taken into the alimentary canal of 

 the Daphnia, whence it is driven through the walls by the 



