26 
Research Bulletin No. 4 
aged one half red and no assurance that some of the male 
gametes in the case of the selfed seeds did not carry S. 
We must now examine the results secured in genera- 
tions later than F D and note whether the hypothesis under 
consideration applies equally well to them. 
It will be recalled that F x red-eared plants that arose 
from homozygous, variegated ears which had been self- 
pollinated (see page 18) yielded in F 2 only red-eared and 
variegated-eared progeny. On our assumption the for- 
mula of the parent variegated ears was VV, but the red 
grains of these ears were VS and the gametes associated 
with them therefore either V or 8 or all 8. Female 
gametes carrying 8 would have produced red ears in Fj 
whether the male gametes carried 8 or V, and female 
gametes with V could not have produced red ears except 
when the male gametes uniting with them carried 8. The 
F x red-eared plants must therefore have been VS or SS, 
the former being expected much more frequently than the 
latter, owing to the rarity of S in male gametes. Only 7 
such red ears were tested and all yielded red and varie- 
gated ears in typical Mendelian ratios, showing that all 
of them were VS like any F x hybrid between red and 
variegated races. Of two F 2 reds from selfed F^s, one 
again yielded reds and variegates and one apparently 
bred true red. Three F 2 reds, from F ± reds crossed by 
whites, yielded reds and whites only — typical Mendelian 
results throughout. 
When F 1 red-eared plants arose from either homozy- 
gous or heterozygous, variegated ears that had been cross- 
pollinated by whites they yielded only red-eared and 
white-eared, never variegated-eared, offspring (see page 
19), just as if they were F 1 ears of a cross of reds with 
whites. By hypothesis the parent variegated-eared plants 
were V — and VV, and their red grains S — and SV (or 
possibly SS). The gametes associated with such grains 
were therefore S and — , and S and V (or possibly all S). 
