1920] COULTER— A LEU RONE COLOR 411 



hope that four intensities of each color could be recognized. This 

 proved impossible, since the series of intensities was practically 

 continuous. At this point, therefore, I was forced to conclude 

 that at least genotypes could not be sharply separated on the 

 basis of color intensity. There yet remained the possibility, 

 however, that color intensity might to some degree depend on 

 genotype, the boundaries of the classes merely being obscured by 

 individual variation. With this in view the whole series of colored 

 grains was arbitrarily divided into several intensity classes, and 

 these classes were planted separately and selfed. 



Class W, indicating colorless, gave six large ears, all of which, 

 of course, showed ioo per cent colorless grains. 



Class R indicated faint red. This was the minimum color 

 intensity, and may best be described by saying that a casual glance 

 would discover no color in such grains. More careful scrutiny, 

 however, reveals an evenly distributed (not mottled or variegated) 

 but very faint aleurone color. In the original count of the parent 

 ear these grains had been classified as red. Only one ear was 

 obtained from this class, but that was very striking. Most of 

 its grains were colorless, but some were the same faint red as the 

 parent, and absolutely none were of any deeper intensity. Viewed 

 at a little distance, this ear would be said to contain ioo per cent 

 white grains. 



Class R', indicating light red, produced two ears, on which the 

 ratios were 0:42:31 and o : 88 : 54 respectively. Without hesitation 

 these were both diagnosed as 0:9:7 ratios, indicating a ppRrCc 

 genotype. 



Class R", indicating red, produced three ears, with respective 

 ratios of o : 76 : 59, o : 1 76 : 63, and o : 24 : 8. One feels safe in calling 

 the first a 0:9:7 and the last two 0:3:1 ratios. The conclusion 

 from this is that ppRrCC or ppRRCc or both have a tendency 

 to produce a more intense aleurone color than does ppRrCc. The 

 question arises whether the appearance of one 0:9:7 ratio from 

 the red class was due to improper delimitation of the classes in the 

 first place, of which there was, of course, every possibility; or 

 whether it might have been due to inevitable overlapping of the 



ing to individual variation. I am 



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