EFFECT OF CONJUGATION 



289 



Table 2 shows that in every week (save the fifth), and in every 

 combination of weeks, the average number of fissions was greater 

 for those that had not conjugated than for those that had conju- 

 gated. Tlie fifth week, as we have already seen, gives, for 

 extrinsic reasons, atypical results. In that particular case the 

 difference in the means is not significant, as is shown by the 

 probable errors in the two cases. For the entire four (or five) 

 weeks, the average number of fissions was about 25 per cent 

 greater in those that have not conjugated. If we take the total 

 number of fissions for each line that was alive at the beginning 

 of the experiment, we find that the average number of fissions 

 was 70 to 75 per cent greater for those that had not conjugated. 

 This is of course partly due to the fact that none of the latter 

 died before the end of the experiment, while a considerable 

 number of the conjugant lines died out early. 



It is of interest to compare the number of progeny produced 

 by the two sets. This is of course obtainable from the number 

 of fissions. The potential progeny produced by the two sets in 

 each of the five weeks is given in table 3. 



As the table shows, each line of those that have not conjugated 

 produced weekly on the average almost exactly two-and-a-half 

 times as many progeny as a line of the conjugants. 



The 61 lines derived from the conjugants had a potential pro- 

 duction all together during four weeks of the experiment of 



TABLE 3 



Experiment 1. Potential number of progeny from those that have conjugated, as 

 compared with those that have not, based on the number of fissions in table 2. 



