Inheritance of Salmon Silk Color in Maize 541 
3. Salmon (Plate LII). Silks light salmon-orange to salmon. The 
color below the husks is similar to that of exposed parts. Microscopic 
sections show only a faint brownish cast to the tissues thruout the 
silks. 
4. Brown (Plate LIII). Silks orange-pink to pale salmon or salmon-buff 
in both exposed and covered parts. Salmon and brown silks intergrade, 
forming a continuous series. The lighter forms are difficult to distinguish 
from the yellowish green silks of No. 1. Both salmon and brown silks 
may have red anthocyanin pigment present, as in No. 2. 
f preliminary studies and indications 
Previous tests had shown salmon silk color to be recessive to green and 
at least partially dominant to brown. Crosses of salmon and brown did 
not give green color in the Fi. This was taken to indicate that these 
colors were recessive for a common factor. The anthocyanin pigment 
present in red silks was shown to be inherited separately by the occurrence 
of all combination classes (green-red, green, salmon-red, and salmon) 
in the F 2 of red x salmon. 
From observation of cultures previously grown, both salmon and brown 
silks were known to occur on dilute sun red, on sun red, and on purple 
plants. Their occurrence on brown or green plants had not been recorded. 
Microscopic examination of the pigments of maize had shown the presence 
of a purple-red anthocyanin pigment in purple, sun red, dilute purple, 
and dilute sun red plants. When the A factor is recessive, no anthocyanin 
develops (except traces in the shank and the inner husks of brown plants) . 
Instead, a yellow or brownish pigment may be formed. A similar rela- 
tion holds with the pericarp pigments. Red pericarp color is due to an 
orange-red or brick-red pigment. Its homolog with recessive A is yellow- 
ish brown, similar in appearance to the brown plant-color pigment. 
The quantity of pigment in salmon silks is so small that microscopic 
sections gave little information. But the color of the salmon silks was 
so similar to the color of thin sections of red pericarp as to suggest the 
possible identity of the pigments. The brown silk might, it was thought, 
be only a dilute form of salmon. These suggestions were further strength- 
ened by the fact that the original salmon-silked plant had red pericarp 
and that the brown silks had been obtained from a plant with bronze 
