No. 565] SHORTER ARTICLES AND DISCUSSION 



59 



Matings to Produce the Third Gen 

 tie one family of this generation will b( 



(1) AA 



(2) AA 



(3) AA 



(4) AA 



(5) Aa 



(6) Aa 



(7) Aa 



(8) Aa 



(1) AA 



(5) 



(9) AA 



(13) AA 



(2) Aa 

 (6) Aa 



(10) Aa 



(14) Aa 



(9) aA 

 (10) aA 



(3) aA 



(7) aA 

 (11) aA 

 (15) aA 



(4) aa 



(8) aa 



ZTwrd Generation Families Produced. — (Note: the numbers 

 in parenthesis are to identify matings and their consequent 

 families.) 



Third Generation 

 Constitution of the Population.— 



128AA + 128Aa + 128aA + 128aa, 



Proportion of Homozygotes in this Generation— 50 per cec 

 of the whole population. 



Fourth Generation Families Produced— The third generatic 

 families, when mated, will produce families as follows: 



Summarized this gives the following fourth generation famili 

 produced : 



