PHYSIOLOGICAL VARIATIONS IN PARAMECIUM 497 



/. Conjugations in the G' series 



This series is from the conjugating mate of the ancestral cell 

 of the G series above. It is interesting as being the only case in 

 which fom' pure lines from both conjugants continued to live as 

 long as the first conjugation test. Unfortunately the vitality did 

 not keep up long enough to make the conjugation records of any 

 value. The first rich cultures on December 28 were tested for 

 conjugations on January 1, 3, 8, and 13, but not one pair was 

 found. The entire series died between January 21 and 30 so 

 we cannot draw conclusions from this one series. 



K. Conjugations in the and P series 



The O and P series were derived from ex-conjugants of the 

 J 8 line which were paired December 3, 1912. Rich cultures were 

 seeded in both series January 24, February 27, and April 14 and 

 tests were made from each in the usual manner. In the O series 

 (January tests) one pair occurred in 13 and none in the P series. 

 In th,e February tests, there was one pair in O 12, none in the P 

 series. In the April tests every line of both the O and P series 

 gave conjugations (9 pure lines of the O series and 9 of the P 

 series representing only two quadrants in eaeh case). O 1 gave 

 1300 pairs; 3, 1377; 4, 1259; O 5, 458; 7, 964; Oil, 18, 

 O 12 507; O 13, 1, O 17, 606, pairs. P 1, gave 200 pairs; P 3, 

 739; P4, 8; P 9, 938; P 10, 95; P 11, 7; P 12, 1072; P 15, 1; and 

 P 17, 253 pairs. 



It is unfortunate that only two quadrants are represented in 

 these series, but enough lines are given to show that wide varia- 

 tions occur in the strength of the conjugating power '(e.g., O 13 

 and P 15 give 1 only as against O 3 and P 12 with 1377 and 1072 

 pairs respectively). 



