PLANT Cotors IN MAIZE 47 
3:1 lot listed in table 13, group 2. None of these should give more than 
two types when crossed with dilute sun red. One gave 46 purple and 
1 dilute sun red (group 7), the latter doubtless from an accidental 
pollination of the dilute sun red mother plant. Two F; browns gave 22 
purple and 24 sun red plants (group 5), and four produced 73 purple and 
85 dilute purple plants (group 6). 
To summarize, all the theoretically possible genotypes of brown plants 
have been found either in F2. or in such F; lots as showed a 9:7 
ratio of brown to green. Since these F3’s are comparable with F, browns, 
they may be added to the F.’s in this summary. Of the twenty-one 
brown plants thus grouped, the numbers found to belong to each geno- 
type are compared below with the calculated numbers. The deviations 
are such as might be expected to occur once in three trials, P equaling 
0.34. The comparison follows: 
aaBB Pipl 
GO 153 Jas Jel eds or Gos bsbeRl! phe wloval 
GO OAEND JEN IPA, 
Observed....... 3 12 6 PA 
Calculated...... Dslel) 9.3(+) 9.3(+) 21 
Difference...... +0.7(—) +2.7(—) —3.3(+) 0 
Later behavior of F2 green VI.— All F, green plants should breed true 
phenotypically in F;. Data from eight such F3; progenies are given in 
table 15, group 1 (page 132). There were observed a total of 179 green 
plants, and no other types. Progenies of sixteen green plants of the 
F, lots listed in tables 3 and 6 (pages 122 and 124), produced by backcrossing 
F, purples to greens, are given in table 15, groups 2 to 5. The total 
number of green plants in these progenies is 311. A single brown plant 
found in one of these progenies is assumed to have been due to acci- 
dental pollination. Green plants are therefore found to breed true green 
as expected, but there is nothing in this fact to indicate that green plants 
of the crosses under consideration are genotypically alike. That the 
five genotypes expected on the basis of the three-factor hypothesis were 
present among the progenies listed in table 15 is demonstrated in the 
next section of this paper. 
