VIRILE SENTIMENT 65 



if it is carrying only albinism, then all its sex-cells 

 can carry albinism alone. But if it carries both 

 blackness and albinism, then one-half of its sex-cells 

 will carry one character, and the other half will 

 carry the other. 



Now it is clear that so long as a pure black 

 individual is crossed with another pure black, 

 sex-cells carrying blackness only can meet. Hence, 

 only a black offspring can result. And in the same 

 way, so long as an albino is crossed with an albino, 

 there is only one kind of sex-cell which can meet, 

 i.e., an albinism-carrying one with an albinism- 

 carrying one. But it is otherwise when an impure 

 or hybrid black is mated with a similar individual. 

 Here the two parents are both carrying two kinds 

 of sex-cells, i.e., those transmitting blackness and 

 those transmitting albinism. Consequently, at sexual 

 conjugation, a male sex-cell which carries blackness 

 has an equal chance of meeting an egg carrying 

 either blackness or albinism. And the same is true 

 of the male sex-cell which carries albinism. If we 

 agree to let A stand for albinism, and B for blackness, 

 then B A will represent a hybrid individual. This 

 individual will be black in colour, although it is 

 carrying albinism, because we have seen that black- 

 ness is dominant and albinism is recessive. We 

 may, therefore, graphically represent the possibilities 

 in this way : — 



A A X B B Parents. 



I 



\ BA + BA +BA I Offspring. 



