,for two cliaracters it is then : 
3 
LA THÉORIE DU CROISEMENT. 207 
2'^— 1, 
/\ 2" V 2" J ' 
,Por three cliaracters it is of course 
'2^ — 1-^ 
,,and in gênerai for any number m of cliaracters the probability œ for 
„pure homozygotes (or the proportional number of pure homozygotes) is 
'2" 
„By similar reasoning the proportion of ail the organisms that will 
,be heterozygotic with respect to ail the m characters is 
,,With two or more characters there will be of course a considérable 
„number of the organisms that are homozygotic with respect to some 
^characters, heterozygotic with respect to others. 
„ïî we call the proportion of thèse z, then 
„And if we let v be the total proportion that contains any heterozygotic 
„ characters (so that v = ^-{-z)^ then 
'2» 1\ 2"*'^ (2" 1)'^ 
— 1 — _ 
2'" 
„These formulae may readily be deduced algebraically or verified by 
„a detailed analysis of a case of two or more characters. It may be worth 
„wlnle to indicate the method followed by taking up the simpler case of 
„two pairs of characters. Call thèse |^ and The gamets formed are 
„ABj Ab, ciB and ah. 
„When thèse combine in ail possible ways (as indicated in the dia- 
grams in Bateson^s Mendelism) thèse give the following results: 
