MECHANISM OF COMPETITION IN YEAST CELLS 



85 



series of experiments in conditions analogous to the former anaerobic 

 ones. The general character of these curves coincides with that of 

 Figure 13. A more careful comparison of the anaerobic series of 1932 

 with that of 1931 shows that the first is characterized by consider- 

 ably smaller absolute values of growth (Table VI) . At the same time 

 Schizosaccharomyces grown separately attains a somewhat higher 

 level in comparison with Saccharomyces than formerly. Thus, the 

 volume of the saturating population of the separately growing Schizo- 



5 8 

 saccharomyces represented in older experiments — ^— = 44.6 per cent 



fa ccharomyces 



Aerobic conditions 



Mixed population 



□ a a. 



T 



Schizosaccharomyces 



. — Saccharomyces 



• * ■ % dnaerobic conditions 



_■ v- Mxed population 



SO 60 



Hours 



^ Fig. 16. The growth in volume of Saccharomyces cerevisiae, Schizosaccharo- 

 myces kephir and mixed population. Above: Aerobic conditions. Below: 

 Anaerobic conditions (1932). 



of that of Saccharomyces (1931), but in the new experiments it is 



3 



■^— = 48.0 per cent (1932). In the experiments of 1932 the relative 

 b.25 



volume of Schizosaccharomyces in the mixed population increased 



also. As a result the decrease of the volume of the mixed population 



in comparison with the volume of separately growing Saccharomyces 



is more pronounced in 1932 than in 1931. 



In spite of the alterations in the absolute values of growth and a 



certain change in the relative quantities of species, the coefficients 



of the struggle for existence which we had calculated for the anaerobic 



