348 LUTHER BURBANK 



whiteness recessive. But if two of these black 

 offspring are interbred, it is an observed fact 

 that among their progeny three out of four indi- 

 viduals will be black like their parents and one 

 of their grandparents, and the fourth one will be 

 white like the other grandparent. 



The Mendelian explains that the factor of 

 whiteness was submerged, dominated by the 

 factor of blackness, in the second generation; 

 but that half the germ cells of these black indi- 

 viduals contained the factor of whiteness, and 

 that by the mere law of chance the union of these 

 germ cells brought together about one time in 

 four two of the cells having the recessive white 

 factor ; such union resulted in a white individual. 



Meantime by the same law of chance the other 

 three matings out of the four brought together 

 in one case two black factors and in two cases a 

 mixture of black and white factors. 



As black is dominant, these individuals having 

 the mixed factors would be individually black 

 (just as those of the first cross were black) ; but 

 their progeny in due course will repeat the 

 formula of their parent by producing one white 

 individual in four. 



It should be explained that the Mendelian, in 

 expressing this formula, usually substitutes for 

 the word "factor," as here employed, the newly 



