Induced Mutational Changes in Yeast 



127 



with the data on species of the genus Saccharomyces (which 

 species are rather close to the altered forms of yeasts), we con- 

 cluded that it has been possible to obtain experimentally, 

 from S. glohosus, new forms which may be referred to the 

 following 3 species: S. paradoxus (group 1); S. chodati 

 (group 2) and S. ellipsoideus (group 4). The forms obtained 



Fig. 4, Fermentation of malt-wort by certain species of 

 Saccharomyces, and by new forms obtained experimentally. 

 1. S. globosus; 2. S. paradoxus; 3. S. ellipsoideus; 4. S. 

 cerevisiae XII. Altered forms produced from .S'. globosus: 

 lA-74/349-1-105-18; lB-74/349-l-105-18m-l-4. Altered 

 forms produced from S. paradoxus: 2A-A37-9/2m-l-29; 

 2B-A37-9/2-l-29d. 



from S. paradoxus may be referred to 2 species : S. ellipsoi- 

 deus (group 4) and S. cerevisiae (group 2). 



These data testify to the fact that by cultivating yeasts of 

 the genus Saccharomyces on their specific substrates, it is 

 possible to induce changes in species characters. The scheme 

 of variation is shown in Fig. 3. Fig. 4 shows the intensity of 

 fermentation and the depth at which malt-wort is fermented 



