1905.] Study of Conjugation in Paramcecium. 379 



Table I. — Differentiation of Conjugants from Non-conjugants. 



Scries. 



Character. 



Constant. 



Absolute difference 

 between non-conjugants 

 and conjugants. 



Relative differ- 

 ence between 

 non-conjugants 

 and conjugants. 



Length 



Breadth 



Index. 



Length and 

 breadth 



Mean 



Standard deviation . . . 

 Coefficient of variation 



Mean 



Standard deviation ... 

 Coefficient of variation 



Mean 



Standard deviation . . . 



Coefficient of correla- 

 tion 



Mean 



Standard deviation ... 

 Coefficient of variation 



Mean 



Standard deviation . . . 

 Coefficient of variation 



Mean 



Standard deviation . . 



Coefficient of correla- 

 tion 



21 -833 ±0 -893 micron 

 4 337 ±0-631 „ 

 1 -517 ±0 -349 per cent. 



8-456 ±0-335 micron 



1-700 ±0-237 



1 -714 ±0 -484 per cent. 



1-510 ±0-171 

 -0-195*±0-121 



0-3107 ±0-0526 



Length 



Breadth. 



Index. 



Length and 

 breadth 



33 -341 ±1 -098 micron 

 6-005 ±0-777 



1 -684 ±0-398 per cent. 



11 -050 ±0 -324 micron 

 2-491 ±0-229 „ 



2 -984 ±0-456 per cent. 



1-416 ±0-155 „ 

 -0-152*±0-110 



0-4072 ±0-0542 



This table shows that the differentiation between conjugants and non- 

 conjugants is strikingly large in both type and variability for all characters. 

 The same is true for the organic correlations between length and breadth. 

 The conjugant individuals, when compared with non-conjugants, are found to 

 be shorter and narrower, and less variable in both length and breadth. The 

 conjugants have a lower mean index — or, in other words, are relatively more 

 slender — and are more variable in shape of body, as indicated both by length- 

 breadth index and by the organic correlation between length and breadth. 

 The conjugants have the length and breadth less highly correlated than the 

 non-conjugants. 



4. To determine whether there was any definite tendency for like to pair 

 with like (homogamy) in the conjugation of Paramecium, the correlation 

 between the two members of conjugant pairs was determined for (a) the 



* The higher variability of the length-breadth index in the conjugants really arises 

 from the fact that the organic correlation between length and breadth is much lower in 

 conjugants than in non-conjugants. 



