2-5 



2.0 



i.o 



o-S 



0.0 



.1 



L-v 



Feb., 1909 



March 



April 

 DIAGRAM IV. 



May 



June 





FIG. 4. Paramecium, Culture I s (constant environment) = broken line; Culture I (varied environment) 

 - continuous line. = point of isolation of Culture I s from Culture I. X point at which Culture I 9 died 

 out. Other details as in Fig. I. 



