INHERITANCE IN ABNORMALITIES 



431 



tirely normal until December 7, five days after conjugation. 

 On that date two of the existing 27 normal individuals were 

 chosen to carry on the race; one of these continued to produce 

 only normals until it was discontinued six days later. By that 

 time it had given rise to 53 normal individuals. This was the 

 largest group of normals produced by race B. 



Chart 7 



The other normal kept on December 7 gave rise to all later 

 individuals of race B, which were kept for 105 days, and 83 

 generations, and had an average proportion of abnormality of 56 

 per cent. The history of this race from this point on is exactly 

 like that of race A. On December 23, 83 of the most abnormal 

 lines were selected from the existing 314, and grouped (table 12). 



