106 



THE STRUGGLE FOR EXISTENCE 



Figures 22, 24 and 25 is almost the same, but there are certain differ- 

 ences concerning secondary peculiarities. For a detailed acquaint- 

 ance with the properties of a mixed population we will consider the 

 growth with a half-loop concentration of bacteria (Fig. 24). First of 

 all we see that as in the case examined before the competition between 

 our species can be divided into two separate stages: up to the fifth 



80 



. P. cau datum. 



9*m W 



K^€V 



• f 



Separately 



v ,aw«, &&&L 



Jn mixed population 

 a 



Fig. 24. The growth of the "volume" in Paramecium caudatum and Para- 

 mecium aurelia cultivated separately and in the mixed population on the buff- 

 ered medium with the "half-loop" concentration of bacteria. From Gause 

 C34d). 



day there is a competition between the species for seizing the so far 

 unutilized food energy; then after the fifth day of growth begins the 

 redistribution of the completely seized resources of energy between 

 the two components, which leads to a complete displacement of one 

 of them by another. The following simple calculations can convince 

 one that on the fifth day all the energy is already seized upon. At 



