AN AMICRONUCLEATE OXYTRICHA. II 



147 



were carried until the death of the animals in both cultures, 

 which occurred on March 14, 1918. 



The twin culture died in the thirty-first generation, the sub- 

 culture of single annuals in the thirty-seventh. Here the aver- 



Fig. 11 Comparison of twin culture (S6T, continuous line) and of subculture 

 (S6TS, broken line) of single animals derived from twin culture, January 25 to 

 March 11, 1918. 



J , 



I I ' 1 



I — tz: \ ! 



I I I 

 I I 1 



h — -■ tzrr. 



Fig. 12 Comparison of twin cultures (S7T, continuous line) and of subculture 

 of single animals (S7TS, broken line) derived from the twin culture. January 

 28 to March 14, 1918. 



age division rate of the single animals was slightly greater than 

 that of the twins themselves. In general, however, the fluctua- 

 tions in the division rate correspond to a remarkable degree. 



