ENDOMIXIS IN PARAMECIUM AURELIA. 



453 



Again the synchronism is very marked throughout the work, 

 while during the initial period (59) it is perfect. The explana- 

 tion of the occurrence of endomixis in every culture during the 

 59th period is undoubtedly due to the marked change of culture 

 conditions to which these subcultures were subjected, when the 

 experiment was initiated in period 58, by isolation of the 's' 



FIG. 8. 



subcultures from their respective main cultures on the varied 

 culture medium changed daily (cf. Figs. 9 to 12). This will be 

 considered in connection with the following experiment, but 

 obviously it is in accord with the results obtained by Woodruff 

 and Erdmann 1 who noted in studying various lines of one race 

 that the reorganization process "may occur a few days earlier in 



1 Journal of Experimental Zoology, 1914. 



