BIPAKENTAL INHERITANCE IN PARAMECIUM 



427 



There is something in the pairing that causes the two individuals 

 to resemble each other more than usual. 



The condition is again the reverse of that called for by the 

 theory that the two members of pairs are sexually differentiated, 



I pointed out on a preceding page the interest of the question 

 as to whether the two members of the pairs differ from each other 

 more than do members of what would have to be considered 

 members of the same sex. I have worked out this matter for a 

 number of periods, for the same organisms dealt with in table 

 41. The results are given in table 42. 



Table 42 shows that the difference between the two members of 

 pairs ('male and female') is on the average distinctly less than 

 the difference between those that would have to be considered 

 members of the same sex in different pairs. It is less than the 

 difference between the 'females' of table 42 in two of the four 

 weeks of table 42, greater in two, and averages practically the 

 same. It is decidedly less than the difference between the ' males' 

 of different pairs, in three of the four weeks; greater in one; it 

 averages distinctly less than for the 'males.' 



Thus, so far as the conditions in experiment 1 are typical, 

 we must conclude that the differences in rate of reproduction 



TABLE 41 



Experiment 1. {This Journal, vol. 14, 1913, p. 286). Mean differences in n^imber of 

 fissions between the two members of pairs, as comparedivith the mean differences of 

 members paired at random. The table includes only those pairs, both members of 

 which lived through the period in question, save the last entry, which gives the 

 data for the actual number of fissions for all the pairs that began the experiment 

 whether they lived to the end or not. 



