110 R. A. Emerson 
such trials, P equaling 0.57. It will be recalled that results like these 
were obtained from a cross of green-anthered purple with dilute purple 
(page 96), and of course the same results were to be expected since the F; 
in both cases is supposed to have been A A Bb Pl Plr’ R’. 
The cross now under consideration has interest from the standpoint of 
the relation of aleurone color to plant color, and also for certain linkage 
relations. The F,; was known to be, with respect to aleurone color, 
AARr. Whether it was CC or Cc was not known, since a strong red 
pericarp made aleurone counts impracticable. The green plant on which 
the F, was backcrossed, was determined by appropriate tests to be C C, 
so that the relation of the F; purple to C is immaterial. The backcross 
resulted in approximately equal numbers of seeds with and without 
aleurone color, there being 109 colored and 110 colorless seeds. The 
colorless seeds must have been ABC Plr'r’? and AbC Plr'r’, and 
should therefore have produced purple-anthered purples and dilute purples 
only; while the colored seeds must have been A BC PI R’r’ and AbC 
PIR’ r’, and should correspondingly have produced green-anthered ~ 
purples and greens only. The results were quite in accord with expecta- 
tion, as is shown in the following comparison: 
Purple, Purple, Dilute 
Color types purple aie ereen Tes purple Green Total 
Ta Ig MMOGs LUE be 
Colored seeds. .... 0 22 0 29° 51 
Colorless seeds... . 28 0 Dilt 0 49 
It has been shown earlier in this paper (page 63) that a linkage exists 
between the factor pair B b and a factor pair, Lg lg, for normal or ligule- 
less leaf, the percentage of crossing-over being about 30. It happens 
that the F, of this cross was Lg lg as well as Bb, B lg having come from 
one parent and b Lg from the other, and that the green plant used in the 
backcross was blg. There is no question here that the purple-anthered 
purples and dilute purples produced from colorless seeds differed with 
respect to the 6b pair only. Their linkage with liguleless leaf, as indi- 
cated by the percentage of crossing-over, was 29.4, or a deviation from 
30 of 0.6 + 2.0. Practically the same linkage relation was found for the 
plants from colored seeds, green-anthered purples and greens. In this 
case the percentage of crossing-over was 27.5, a deviation from 30 of 
