FINITE POPULATIONS 



57 



of these influences renders unlikely the possibility that the 

 recombinations of the F3 and subsequent generations could 

 advance very much outside the recombination of the F2. 



Figs. 14-17. Types and frequencies expected in the F3 from self -pollinat- 

 ing four of the F2 plants of Fig. 11. Note that in the F3 the frequencies of 

 each selfing still tend to align themselves in accord wdth the "recombina- 

 tion spindle" of the F9. The scale is that of Fig. 9. 



Although this conclusion is based on theory, it is in accord 

 with practical experience. In such endeavors as attempting 

 to recombine the desirable qualities of two inbred lines of 

 maize, it is one of the problems of modern corn breeding that 



