ALCOHOLIC FEKMEtfTS. 183 



are formed from two old cells which, before budding in the 

 direction of their common longitudinal axis, usually simul- 

 taneously throw out several buds as branches. The asci very 

 frequently remain united in pairs, or each united to a vegeta- 

 tive cell. Spores 2 to 4, which on germination again 

 give rise to clusters. Occurs on decaying grapes and in 

 wine-yeast at the commencement of fermentation. Fermen- 

 tative action doubtful." 



In Hansen' s cultures of film-formations of the Saccharo- 

 mycetes, colonies of the above-mentioned appearance were 

 found in old films of the six species first investigated by 

 hi-m. And since Hansen never found a definite species 

 among his cultivations which could be identified as Reess's 

 Saccharomyces conglomeratus, he is inclined to assume 

 that the cell-colonies mentioned of the different Saccharo- 

 mycetes are identical with this species. 



The different races or species of yeast may be divided 

 into two groups, according to the kind of fermentation to 

 which they give rise, namely : bottom-yeasts and top-yeasts. 

 In spite of many assertions to the contrary, it has not hitherto 

 been possible to bring about an actual conversion of top-yeast 

 into bottom-yeast, or vice versa. The investigations of Hansen 

 and Kuhle show that it is certainly possible for a bottom- 

 fermentation yeast to produce transitory top-fermentation 

 phenomena ; these, however, quickly disappear with the pro- 

 gressive development of the yeast. When formerly it was 

 stated that by the continued cultivation of, e.g., bottom-yeast 

 at an elevated temperature, this could be converted into top- 

 yeast, these old experiments can only be explained on the 

 assumption that the bottom-yeast employed was impure and 

 contained an admixture of top-yeast, which at the elevated 

 temperature gradually developed at the expense of the 

 bottom-yeast, until it finally constituted the chief portion 

 of the yeast. 



