1h R. A. EMERSON 
The natural supposition is that there is here concerned still another 
form of the R factor, such that, while it does not allow color to develop 
in the anthers, does nevertheless result in the development of some antho- 
cyanic pigment in other parts of the plant. The dilute sun red plant used 
as one parent of this cross was found to be A ¢ R with respect to aleurone. 
The factor particularly concerned in the behavior here reported is there- 
fore assigned the designation R”. The F, plants are accordingly assumed 
to have been A A Bb PI plR' R”®. The frequency distribution for the 
eight color types observed in F2 approached the theoretical distribution 
so closely that deviations of the magnitude observed might occur by chance 
nearly three times in any ten such trials, P equaling 0.72. The com- 
parison follows: 
Plant color Purple Purple Sunred Sunred eae ee Pe ae Total 
Anther color Purple Green Pink Green Purple Green Pink Green 
Observed... 212 77 66 22, 66 23 22 3 491 
Calculated. 207 69 69 23 69 23 23 8 491 
Difference... +5 +8 —3 —l] —3 0 —] —5 0 
One F2, a green-anthered purple, was tested in F;. This pliant bred 
true, producing 128 green-anthered purples and no other types. 
It is unfortunate that the relation of aleurone color to plant color in 
this cross afforded no check on the assumption that the observed behavior 
with respect to anther color of dilute purples and reds was due to a factor 
belonging to the allelomorphic series R’, R%, 7’, 7°. - True, the Fy plant 
tested was heterozygous with respect to aleurone color, but this was 
known to be due to Cc. Since no further tests have been made, the only 
evidence in support of the assumption of a factor R” is the very close 
fit of observed with theoretical frequency distributions, the fact that colored 
and green anthers in purple and sun red types of many other crosses have 
been found to be due to the R factor, and the demonstrated presence of 
R in the green-anthered sun red plant used in the cross. 
Summary of results involving the allelomorphic series R’, R’, R™, 1’, r?, r™ 
Crosses of brown with green of type [Vg have been shown to result 
in purple Fy’s, and in eight color types in F2 in a numerical relation approxi- 
mating 81:27:27:9:27:9:36:40, or in six major color types, anther color 
being disregarded, in approximately the relation 108:36:27:9:36:40. 
