104 R. A. EMERSON 
these green plants were crossed with dilute sun reds which were F,’s of 
crosses between dilute sun red and green IVg. The results were dilute 
purple and green plants in the relation 328:338 (table 45, group 3), a 
deviation from a 1:1 ratio of 5.0 + 8.7. Since the heterozygous dilute 
sun red plants were A A 6 b pl pl R’ 7", the green plants crossed with them 
are assumed to have been Ab PIR’. That this assumption is correct 
appears the more evident from the fact that the green plants were homo- 
zygous for colored aleurone, and hence A C R. 
Green IVg x green VIc.— Twelve crosses between green plants of type 
IVg and green plants of type VIc gave a total of 159 F, plants, all dilute 
sun red. With respect to aleurone color, all the type IVg plants concerned 
in these crosses were known to be AcR, and, in fact, were in general 
use as C testers for aleurone color. With respect to plant color, therefore, 
they are assigned the constitution Ab pl R’. Of the type VIc greens, 
four were known to be A testers for aleurone color, and were therefore, 
with respect to aleurone color, aC R. Their plant-color constitution is 
accordingly set down as ab pl R’. Six of the type VIe greens had an 
aleurone-color constitution of aC yr, their plant-color genotype being 
accordingly ab plr’. The other two VIc greens were certainly a b pl, 
but whether they were R’ or r” is unknown. 
In F,, dilute sun red and green plants were present in the ratio 420: 291 
(table 46, group 1, page 154). From an F; of the genotype A ab b pl pl 
plus: R’ r" or R’ Rk’, a 9:7 ratio of dilute sun red to green is to be expected 
in F2, since both A and 7’ or R" are assumed to be necessary for the pro- 
duction of anthocyanic pigment, which distinguishes dilute sun red from 
green. The theoretical ratio for a total of 711 individuals is 400:311. 
The observed deviation from this ratio, 20.0 + 8.9, is such as might 
occur by chance about once in eight trials, P equaling 0.18. 
Two F, plants backcrossed to green VIc, ab pl R’, gave 66 dilute sun 
red and 58 green plants, and two backcrosses with green IVg, A b pl’, 
gave 96 dilute sun reds and 96 greens, equality of the two classes being 
expected in the case of both crosses (group 2, table 46). 
That the two parent types of green occurred in F», is shown by their 
relations to aleurone and pericarp color. In the case of every cross, green 
plants were produced from both colored and colorless seeds. Those 
from colored seeds could have been only Ab pl R’. Since some seeds 
were colorless because of a a and some because of cc, both parent types of 
green should have been present in the lots grown from colorless seeds. 
