496 



AUSTIN RALPH MIDDLETON 



only during the period of reorganization after conjugation, when 

 the fission rate in all was extremely low. As soon as the 'nor- 

 mal' fission rate was resumed, the balanced-selected set of origi- 



10 12 14 



A 



Fig. 17-a Curves of variation of the lines of Experiment 3-C (balanced selec- 

 tion after conjugation) for the first 6 days of the experiment. The continuous 

 line is the curve of the fast set; the broken line, the curve of the slow set. The 

 ordinates are the numbers of lines; the abscissae, the number of generations. 



Fig. 17-& Curves of variation of the lines of Experiment 3-C (balanced selec- 

 tion after conjugation). The continuous line is the curve of the fast set; the 

 broken line, the curve of the slow set. The ordinates are numbers of lines; the 

 abscissae,* generations. 



nall}^ fast ex-conjugants at once resumed its place in advance of 

 the balanced-selected set of originally slow ex-conjugants and 

 continued to divide more rapidly throughout the rest of the 

 experiment. 



