ON THE SMALL GRAINS 



Biff en was able to analyze the diverse qualities of 

 the various wheats with which he experimented 

 and to discover that different groups of unit char- 

 acters operated differently in heredity. Some of 

 the pairs showed dominance and recessiveness ; 

 others showed an irregular or partial dominance; 

 while other pairs showed the blending of charac- 

 ters, so that the offspring was intermediate be- 

 tween the parents, there being 110 apparent ten- 

 dency to dominance or recessiveness. 



Yet all of these characters, whether manifesting 

 the phenomena of dominance in the hybrid of the 

 first generation or not, showed the same tendency 

 to segregation in the succeeding generation, and 

 to segregation along the familiar Mendelian lines; 

 that is to say, one offspring in four would reveal 

 the first character only, the second and third off- 

 spring were mixed as to the pair of characters, 

 and the fourth would show only the second 

 character. 



It was necessary only to plant the individual 

 grains of wheat in plots by themselves, and to note 

 the qualities of the grains of each (that is to say, 

 the qualities of the offspring of the first filial gen- 

 eration) to make sure as to the position of each 

 individual in the Mendelian scale (whether pure 

 or mixed in its heredity as to its given factor), and 

 thus to be able to select pure types that would 



[59] 



