322 



H. S. JENNINGS 



TABLE 18 



Experiment 11 d. Paramecium aurelia. Nunihcr of fissions for three successive 

 days, in ten non-conjugants from the slide series D {of fig. 2), and in ten progeny of 

 the conjugants {K, fig. 2), that had lived in watch-glasses since May 15 (d = dead). 



as the conjugants (A') (cultivation in watch glasses since May 15) 

 were not less vigorous than the progeny of the conjugants. but 

 at least equally vigorous with them. The only difference between 

 the non-conjugants of this present experiment (D) and those of 

 the previous one (H) is that those in the present experiment were 

 cultivated about a month longer on slides (May 15 to June 7). 

 Apparently this is the cause of the weakness of these animals. 



But it is clear that the progeny of the non-conjugants of this 

 slide series D are now in a weakened, depressed condition, while 

 both conjugants and non-conjugants from watch glass cultures 

 are vigorous. This gives us an opportunity to determine the 

 effects of conjugation in such a depressed culture. Before under- 

 taking this, two additional tests were made to see if the depressed 

 condition of the progeny from the slide series D was beyond 

 doubt. 



Experiment 11 e. The first of these consisted again of ten lines 

 of the non-conjugant slide series D, ten from the conjugants 

 (watch glass series, K). The experiment continued from July 6 

 to July 28. 



In this experiment, as soon as any line of either set died out, 

 « it was replaced from some other line of the same set. The number 



