344 MICRO-ORGANISMS AND FERMENTATION. 



following section), and subsequently in his notes regarding 

 Johannisberg II. He found that the temperature limits for 

 budding in wort are 37 to 38 C. and 0-5 C. ; for spore-for- 

 mation on gypsum blocks 33 to 34-5 C. and 2 to 3 C. 

 Further publications we owe to Aderhold, Hotter, Kayser, 

 Marx, Miiller-Thurgau, Seifert, Wortmann, and others. As 

 examples of the different biological characters observed in 

 wine yeast, we will discuss more closely a few of the species 

 described by Aderhold. 



Johannisberg I. has round or oval-pointed cells ; in the 

 young film produced at 26 to 27 C.* the cells are oval ; spores 

 appear in 28 to 30 hours at 25 to 26-5 C * 



Johannisberg II. has large oval cells, characterised by 

 longish but blunt ends. The film cells are round, oval, and 

 sausage-shaped ; spores are formed within 23 to 24 hours. 



Kreuznach has the same cell-formation as the previous 

 species, but somewhat smaller ; film cells like Johannisberg I. ; 

 spores in 30 hours. 



Mulheim has broad, oval, and, less frequently, round cells, 

 with short pointed ends smaller than the previous species ; only 

 round and oval film cells ; spores within two to three days. 



Walporzheim I. has round cells, the oval forms scarcely 

 pointed ; often budding colonies in the film, elongated links 

 forming an axis for the colony surrounded by round cells ; 

 spores in 80 hours. 



Piesport ; predominantly elliptical cells without pointed 

 ends ; only spherical cells in the film ; spores in 23 to 24 

 hours. Grown on solid substrata, differences can be observed 

 in the development of colonies. 



Pure selected races have gradually been introduced in large 

 numbers into the wine fermentation by Miiller-Thurgau. 

 Wortmann, Kayser, Jacquemin, the author, and others. 

 Miiller-Thurgau and Wortmann, amongst others, have indi- 

 cated and proved the importance of these pure cultures, as 

 not only the must but also the fermented product, the wine, 

 is dominated by the pure yeast throughout every stage of its 

 development, extending, it may be, through many years. f 



* Similar temperatures hold good for the following species. 

 . "j" See the section on the behaviour of Saccharomycetes with sugars, etc. 



