442 RUTH J. STOCKING 



Of these 225 pairs, in the first experiment both members in 

 48 gave normal lines, both members in 26 gave abnormal lines, 

 while in 40 the two members gave lines diverse in this respect. 

 The total number of normal individuals was therefore 136, of 

 abnormal individuals 92. In the second experiment, both mem- 

 bers in 7 gave normal lines, both members in 69 gave abnormal 

 lines, while in 21 the two members gave lines diverse in this 

 respect. The total number of normal individuals of experi- 

 ment 2 was therefore 35; of abnormal individuals 159. In 

 Experiment 3, both members in 8 pairs gave normal lines, and 

 both members in 6 gave abnormal lines; pairing was perfect. 

 The total number of normal lines of Experiment 3 was there- 

 fore 16; of abnormal lines, 12. 



How many pairs with both lines abnormal should we expect 

 to find in these cases if pairing does not affect the distribution 

 of abnormalities? In the first experiment n is 92, while m is 

 228. Applying the formula we find that the expected number 

 of pairs with both members abnormal is 18; the actual number is 

 28. In the second experiment n is 159 while m is 194. By the 

 formula the expected number of pairs with both members abnor- 

 mal is 66, while the actual number is 69. In the third experi- 

 ment n is 12 while m is 28. The expected number of pairs is 2, 

 the actual 6. In the same way the expected number of pairs 

 with both members normal is in the first experiment 40, while 

 the actual, number is 48; in the second experiment the expected 

 number is 3 the actual 7 ; in the third, the expected number is 4 

 the actual 8. 



It is therefore clear that in all three experiments the number of 

 like members of pairs is greater than would be the case if the 

 pairing had no effect on the distribution of the abnormalities. 

 Conjugation tends to cause the descendants of the two menders of 

 pairs to become alike in respect to abnormality and norynality. 



Some of the exconjugants never divided after separation. The 

 same question may be examined with respect to them. Do the 

 two members of a pair tend to have the same fate in this respect? 

 There were 72 exconjugants that never divided, out of the 228 

 of the first experiment, and 27 out of the 194 of the second 



