BLENDING INHERITANCE 



189 



varying doses among these fifteen possibilities, as indi- 

 cated by the numbers in the squares. It is evident, 

 therefore, that several shades of brown will be rep- 



FIG. 55. Diagram to illustrate Nilsson-Ehle's case of trihybrid red 

 wheat. The large screwheads each represent a single determiner for 

 the red character. The small screwheads symbolize the absence of 

 the red character, or white. The number in each square indicates 

 how many doses of the "red" determiner is present. For further 

 explanation see text. 



resented depending upon the number of doses of the 

 brown determiner in each instance. 



Figure 54 shows how these different shades of 

 brown arrange themselves in the manner of a fre- 

 quency polygon of fluctuating variation with the 

 greatest number in the halfway class and the least 



