432 



RUTH J. STOCKING 



Each one of the 83 lines was divided into two sub-lines, in one of 

 which the most normal were selected, in the -other the most 

 abnormal. In six lines the continuous selection of normals was 

 possible. Their history is given in chart 8, and table 13 gives 

 the data from them. Two of these lines produced abnormals 

 the last day they were kept, and a third was entirely normal 

 for only four days before death; the selection has slightly de- 

 creased the proportion of abnormals produced, but has not elimi- 

 nated the abnormal character. But the three other lines became 

 entirely normal some time before death, as the table shows. 

 Selection here has had a decided effect; has entirely eliminated 

 the abnormal character. 



Chart 8 



Genetic history of the six lines of Race B in which the selection of normals was 



continuous 

 (n = normal; ah = abnormal; D = died out) 



Line January February 



20 22 24 26 28 30 1 3 5 7 9 



lab 4ab 2ab 

 B2 4n8n 2n 4n 2n 4n 8n 2n 4n 4n D. 



B3 



8n 4n 8n 6n 8n 8n 2n 4n 3n D. 



Line 



25 27 



B4b2 2n 



December 



29 31 2 



3ab lab 2ab 

 In In In 



2ab 



4 6 

 2n In 



8n 



B4il 



lab 3ab 

 2n 2n 2n 2n 2n 2n In 



January 

 10 12 14 



2n 5n 2n 



16 18 20 22 24 

 2n 4n 4n 8n D. 



3ab lab 2ab 

 3n In In 2n 2n 4n D. 



B7 



3ab 2ab 2ab lab 2ab lab 2ab lab lab Sab lab lab 

 In 2n 2n 2n 2n 2n In In In 2n In In 3n 2n 7n D. 



B15 



2n2n 



2ab 

 2n 2n 



lab 

 In In 



D. 



In nine lines the continuous selection of abnormals was possi- 

 ble. The history of three of them is given in chart 9 and table 

 14 gives the data from them. The proportion of abnormality 

 in most of these lines has been somewhat raised by this selection 

 over that of the race as a whole ; but not to such an extent as in 



