EFFECT OF CONJUGATION 



341 



TABLE 22 



Experimerit 13 c. Paramecium aurelia. A' umber of fissions, and number of deaths, 

 in each of the sets of 16 parallel cultures belonging to six of the conjugant lines 

 of table 33, between January 28 arid February 15. For each line, the minimum 

 and maximum member of fissions in the cultures that lived through the period are 

 given. Thus, in line 1, one of the 16 sets gave 15 fissions, another 20. 



the 16 sets of line 1 were flourishing under precisely the same 

 treatment. 



Later, lines 2 and 3 began also to die out. On March 7, line 2 

 was extinct, while of line 3 one set still existed. Line 1 continued 

 to flourish; 16 sets still existed March 7. For other purposes 64 

 sets of line 1 were kept in propagation till April 17. 



'Non-conjugant' lines. Later, the rapid line 1 and the slow 

 line 14 of the 'non-conjugants' (of table 33) were compared 

 similarly, beginning February 26. Sixteen sets of each were put 

 in progress. Line 1 continued to multiply rapidly, line 14 slowly; 

 by March 20 the maximum number of fissions in the former was 

 17, in the latter 6. At this date an attempt was made to increase 

 the numbers to 64 parallel sets for each line. But it was found 

 impossible to get 64 sets of line 14 into existence, owing to the 

 great numba:- of deaths. On March 31 the last set died out, and 

 the non-conjugant line 14 became extinct. At this time there 

 were 64 sets of line 1, which were continued till April 17, when the 

 experiment was abandoned. During the last two weeks there 

 were few fissions even in line 1 . 



Thus all of the lines having a slow rate of fission died out, even 

 though the attempt was made to keep up 16 parallel sets; and 

 this under conditions in which the lines with rapid fission con- 

 tinued to flourish. Although all were treated alike, only the two 

 most rapid lines, No. 1 of the conjugants and No. 1 of the non- 

 conjugants, continued to Uve till the close of the experiment, 

 April 17. 



