SACCHAROMYCES VINI MUNTZII 243 



Lendner, Marx, Miiller-Thurgan, Nastjukow, Osterwalder, Seifert, 

 Wortmann, Jacquemin, Kayser and Jorgensen. 



The most characteristic are the Johannisberg I and II yeasts, and 

 S. vini Muntzii. We shall mention these rapidly. 



JOHANNISBERG YEAST I. Wortmann 1 



This species possesses round, oval, or pointed cells. It forms a 

 scum composed of oval cells at 26-27 C. The ascospores appear at 

 25-26 C. at the end of 28 to 30 hours. They germinate according to 

 Marchaud after having copulated. 



JOHANNISBERG YEAST II. Wortmann 



This yeast has been described by Wortmann and Aderhold. 2 

 It possesses oval cells longer than the preceding yeast, but never 

 pointed. The limits of temperature for budding on beer wort, accord- 

 ing to Hansen, are 37-38 and 0.5 C. Ordinarily it is a bottom 

 yeast. It sporulates very abundantly on the plaster block. The 

 temperature limits for sporulation are 2.3 and 33-34.5. The as- 

 cospores are to the number of four in each asc. It has been shown 

 that they fuse more often two by two before germinating and under- 

 going a true copulation (parthenogamy) 3 (Fig. 35). Germination is 

 accomplished by budding at some point on the copulation canal. This 

 species forms a scum composed of round or sausage-shaped cells. 



SACCHAROMYCES VINI MUNTZH. Kayser 



This yeast was found by Kayser 4 on grapes. It is made up of 

 cells in chains which possess a vacuolar protoplasm and die at about 

 55. The ascospores form at the end of about 42 hours at 25. This 



1 Wortmann, J. Landw. Jahrbucher, XXI, 1892. 



2 Aderhold, R. Die Morph. der deutschen Sacch. ellipsoideus Rassen. Landw. 

 Jahrbucher, XXIII, 1894. 



3 In this yeast the fusion of ascospores exhibits very curious characteristics. 

 In a certain number of cases the zygospore, formed by the union of two asco- 

 spores, commences to germinate before nuclear fusion has commenced. The two 

 nuclei take a position in the middle of the copulation canal and fuse when the 

 first bud forms. At the time when nuclear fusion takes place the nucleus which 

 results from it quickly elongates similar to a bud and divides by amitosis in such 

 a way as to furnish a nucleus to the bud. Sometimes, however, nuclear fusion 

 does not seem to be accomplished. The two nuclei join and seem to divide simul- 

 taneously in a manner to form four nuclei, two of which remain in the zygospore 

 and the other two enter the bud. 



4 Kayser, E. Contr. a 1'etude des levures de vin. Ann. de PInstitut Pasteur, 

 t. VI, 1892, et les Levures, Masson et Gauthier-Villars, editeurs, 2 e ed., 1905. 



