64 THE MENDEL JOURNAL 



the blending of the characters carried by the sex-cells 

 of the two parents. Had blending occurred, black- 

 ness as such, and whiteness as such, would have for 

 ever disappeared. When blackness is crossed with 

 whiteness, if blending takes place, we should expect 

 to find a diluted blackness. And the diluted blackness 

 of the first generation, when bred with diluted 

 blackness, should on this hypothesis give no other 

 individuals but those of diluted blackness ; and it 

 should do this for generation after generation. 

 When crossed with albinism, a dilute black should 

 give a diluter black, but not blackness as black as 

 the original, and albinism as pure as the first albino 

 introduced. It is clear, then, that the blended 

 hypothesis of inheritance fails completely in this 

 case. And it similarly fails in a large number of 

 other cases, comprising a wide range of characters. 



Will the hypothesis of segregation give us an ex- 

 planation of the ascertained facts ? Assuredly it 

 does. Let us proceed to see how. The doctrine of 

 segregation assumes as a fundamental proposition 

 that when two sex- cells unite, one carrying black- 

 ness and the other albinism, these two qualities do 

 not blend or fuse in the single cell which results, 

 but remain distinct ; and that at the ultimate 

 cell-divisions by which the sex-cells of the new 

 individual will separate out from its body cells, 

 these two qualities will be found distinct from each 

 other, and carried in different sex-cells. If the in- 

 dividual is carrying only blackness, then, of course, 

 all its sex-cells will carry blackness. iVnd, similarly. 



