THE EVOLUTION OF LIVING BEINGS. 71 



,,shall happen is the product of the separate pro- 

 babilities for each. 



,,Now we know that the probability x for the 

 ,,homozygotic condition with respect to one cha- 

 ,,racter is: 



2 I 



X = 



2 n 



,,For two characters it is then: 



,For three characters it is of course. 



,,and in general, for any numbers of characters, the 

 probability x for pure homozygotes (or the pro 

 ,,portional number of pure homozygotes) is 



x = 



,,By similar reasoning, the proportion of all the or- 

 ganisms that will be heterozygotic with respect to 

 ,,all the m characters is 



nro 



,,With two or more characters, there will be of course 

 ,,a considerable number of the organisms that are 

 ,,homozygotic with respect to some characters, 

 ,,heterozygotic with respect to others. 

 ,,If we call the proportion of these z, then 



,,And if we let v be the total proportion that con- 

 tains any heterozygotic characters (so that v = 

 y + z), then 



