PLANT Coors IN MaAIzE 113 
It has been noted that these results are wholly unlike those for crosses of 
brown with green reported in an earlier section of this paper, and are 
similar in general, tho with marked differences in detail, to previously 
discussed crosses of brown with dilute sun red. As an interpretation of 
these results, it has been assumed that, in addition to the three pairs 
Aa, Bb, Plpl, a fourth pair—members of a multiple-allelomorph 
series, such as R’ R’, r’ R’, or R’ r? — is concerned. It has been assumed 
further that R* or 7’ is necessary ordinarily for the development of dilute 
purple and dilute sun red and for the appearance of purple and pink 
anthers in purples and sun reds, respectively, while R’ R’ or r’r* is 
necessary for green anthers of purples and sun reds and for the con- 
version of dilute purples and dilute sun reds into wholly green plants. 
Similarly, the appearance of green-anthered dilute purples and dilute 
sun reds in a single cross has been ascribed to R” R”. The relation of 
the R allelomorph to both aleurone color and plant color has afforded 
reliable tests of the hypothesis. Other tests have consisted of the 
behavior in later generations of the several F, color types and the results 
of intercrosses between these types. Neither of these tests has been carried 
to the point of exhausting all the possibilities, but in all a considerable 
number of tests have been made and all have given results in support of 
the hypothesis. A single linkage test, involving the Bb pair with leaf 
type, Lg lg, has afforded added support. On the whole, therefore, the 
hypothesis has been, if not substantiated, at least rendered highly probable. 
RELATION OF ALEURONE FACTORS C’c AND Pr pr TO PLANT COLOR 
The relations of the aleurone factors A and R to plant color have been 
noted repeatedly in this account. A single observation suggests a rela- 
tion between the aleurone-factor pair Cc and leaf color. Culture 2909 
came from colored seeds of a selfed ear showing a 3:1 ratio of colored to 
white seeds, and therefore heterozygous for a single pair of aleurone-color 
factors. Several ears in the resulting progeny also gave 3:1 ratios. Tests 
of four plants with aleurone testers gave conclusive evidence that the 
Cc pair was the one concerned. One selfed plant of the lot, 2909-32, 
had 318 colored and 105 white seeds. Both the colored and the white 
seeds produced only sun red plants, some with green and some with pink 
anthers, indicating the genotype A A BBC cpl pl k’ Rk’. All the plants 
showed strong sun red pigment in the sheaths and the outer husks, but — 
