EFFECT OF CONJUGATION 



365 



It will be observed from table 28 that even in that part of the 

 range where the non-conjugant lines are found, the conjugant 

 figures are much less heaped up near the mean than are those for 

 the non-conjugants. This shows clearly that the greater variabil- 

 ity of the conj ugants is not due alone to an extension of the range 

 of variation toward the lower end ; but also to a scattering of those 

 lying near the mean. If, for example, we omit in Experiment 15 

 all the conjugant lines lying lower (in table 28) than any of the 

 non-ccTnjugant lines, we still find the variation for the conj ugants 

 to be much greater than that for the non-conjugants. In Experi- 

 ment 15, making the omission mentioned, the coefficient of varia- 

 tion for the conj ugants would be 16.776, as compared with but 

 8.585 for the non-conjugants. 



Conjugation, then, increases variability in reproductive power. 

 The next question is: Are these differences inherited, so that 

 in this way differentiated races are produced? To this question 

 were mainly dedicated Experiments 13 and 15, and, as the account 

 given in the text shows, the differences thus produced are inherited. 

 In wild cultures, such as that of Experiment 1, this question 

 cannot be answered so clearly, since the differences in fission rate 

 existing before conjugation are likewise inherited and the effect 

 of conjugation is only to increase the number and extent of these 



TABLE 28 



Distribution of the number of fissions for the lines of desccndaiits of conj ugants, as 

 compared loith those from non-conjugants, for certain periods in experiments 1 

 and 15. {The table shows, for example, that in the first two weeks of experiment 

 1, three of the conjugant lines did not divide: four divided once, etc.) 



