INHERITANCE IN ABNORMALITIES 



433 



race A. Pedigrees of two of these lines are given in figures 15 

 and 16. 



TABLE 13 



Data from the six lines of Race B in which the selection of normals was 



continuous 



Chart 9 



Genetic history of three of the lines of Race B in which continuous selection of 



abnormals was made 

 {n = normal; ah = abnormal) 



Dec. January 



31 2 4 6 8 10 12 14 16 



In In In In 



lab 3ab 3ab Sab Sab 2ab 



2n 



3n 3n 



lab lab lab 



3n 



18 20 22 24 26 

 Dead 



In 



2ab 2ab 40,b 2ab Sab lab lab 2ab 2ab 4ab lab lab Dead 



In 3n 2n 



2ab Sab lab 2ab 6ab 4ab 4ab lab 2ab 4ab lab Dead 



We have therefore in race B a group of individuals consti- 

 tuting a clone, which after the fifth generation and the pro- 

 duction of 32 individuals, gave rise to two diverse groups, with 

 different hereditary characteristics. One group was entirely nor- 

 mal; the other group showed a large and constant proportion 

 of abnormals. Later from this abnormal group, by continued 

 selection in opposite directions, lines were isolated which showed 



