546 
E. G. Anderson 
One of the crosses of the original salmon-silked plant, A b pi sm, was 
with a purple plant with green silks. A B PI Sm, related to the bronze 
stock. The progeny consisted of purple and sun red plants with green and 
salmon silks, showing the parent to have been heterozygous for both 
PI and Sm. Two small plantings gave the following distributions.: 
PI Sm, 26; PI sm, 7; pi Sm, 4; pi sm, 23; whereas equality of the four classes 
would be expected if the factors were independent. This was obviously 
a linkage relation. The factor PI was known to be linked with a factor 
Y for yellow endosperm fEmerson, 1921). Tests of the linkage relations 
within this group are given in a later section of this paper. 
Relation of salmon silks to the A factor 
From an outcross of the original salmon-silked plant with one heterozy- 
gous for brown silks and for the A factor, several plants were selfed. One 
sun red plant was homozygous recessive for the salmon silk factor and 
heterozygous for A and B. Thirty-four sun red and dilute sun red plants 
had salmon or brown silks. Two others were first noted as green but were 
presumably a light brown, both having white pericarp. Eleven green 
plants appeared, all having green silks. Later observations on green and 
brown plants of other families segregating for both a and sm have like- 
wise failed to reveal any green plants with other than green silks. That 
this is not due to linkage is shown by the linkage of Sm with the PI factor, 
which is known to be independent of A, and by the fact that the green 
plants have green silks in families that are homozygous recessive sm. 
Relation of salmon silks to the R factor 
Two questions of interest arose regarding the relation of salmon sik 
color to the R series of allelomorphs. The first was the relation of cherry 
pericarp color to the intensity of color in salmon or brown silks; the second 
was the possibility of the occurrence of salmon silks on green plants of 
the constitution R 3 A b PI or R° A b pi. 
To test the effect of cherry pericarp, a sun red with brown silks, 
A B pi sm r r , was crossed with a dilute purple with cherry pericarp and 
green silks, A b PI Sm r ch . Backcrosses gave a few plants with cherry 
pericarp and brown silks. They were not noticeably different in silk 
color from the white-pericarp plants of the same families. 
