84 R. A. EMEeRSoNn 
For Aa R?’ R’ the aleurone-color ratio must be either 9:7 or 3:1, depending 
on whether the third aleurone-factor pair is Cc or CC. The Fs: purple 
plant 2960-7 showed a 9:7 aleurone-color ratio with 86 colored and 74 
colorless seeds, AaCcR R, while the F3; plant 4956-1 exhibited a 3:1 
ratio with 213 colored and 67 colorless seeds, AaCCRR. Another 
purple plant of the same F; progeny, 4956-32, exhibited a 3:1 aleurone- 
color ratio and threw only green-anthered purple and sun red plants. Its 
genotype must have been AABBCc PlplkR’ R’. Thus it is often 
possible, from behavior in the following generation, to know the genotype 
not only with respect to plant color but for aleurone color as well. This 
is particularly true when the B factor is present. 
Of the twenty-four sorts of behavior possible, according to hypothesis, 
for F, purples of the cross under consideration, four sorts have been 
exhibited in F3; and a fifth shown in Fy. This is far from an adequate 
study of the F2 purples. All that can be claimed, therefore, is that, so 
far as they go, the results are in accord with the hypothesis. 
Behavior of other F: color types.— Only cne F2 sun red plant with pink 
anthers, 2961-4, was tested in F;.. It produced sun reds with pink and 
sun reds with green anthers, dilute sun reds, and greens. Since anther 
color was noted for only a part of the plants, it has to be disregarded in 
classifying the F; progeny. The color types sun red, dilute sun red, 
and green occurred in the numerical relation 114:23:57. Of the eight 
possible genotypes of pink-anthered sun red, only three could throw 
these three color classes—AaBbr'r’, AABDbR’r, and AaBb Rr. 
From the first genotype a 9:3:4, from the second a 12:3:1, and from the 
third a 36:9:19, relation should exist between the Fs; classes. The poor 
fit of observed numbers to the 9:3:4 relation makes it improbable that 
the first genotype is concerned, there being only about one chance in 
twenty-two that the observed deviations are due to errors of random 
sampling, P equaling 0.045. The comparison follows: 
Color types Sun red pie Green Total 
Ila IVa Via, ¢ 
Observed. eles A Raa era ata 114 23 57 194 
Calculated! ssc 1 wae Wii Rees eerie 109 36 49 194 
DitlerenCer:. hai cecs = see eee +5 —13 +8 0 
