54 R. A. EMERSON 
of behavior were exhibited in F3; makes it seem likely that the deviations 
in F, were due mainly to chance. 
Sun red Ila x brown V.— A single cross of brown with sun red gave 
purple plants only, as was expected. Since both parents were homozygous, 
all the F; plants should have been of the genotype Aa BB PIpl and 
should have produced in F, the four types purple, sun red, brown, and 
green, in the relation 9:3:3:1. The three F.2 progenies of this cross are 
recorded in table 23 (page 137). The expected color types were produced 
in approximately the expected numbers. The odds against the observed 
deviations’ being due to chance are three to two, P equaling 0.40. A 
comparison of observed with expected distributions follows: 
Color types Purple Sun red Brown Green Total 
a la Ila V Via 
@Observeds ac fesse ne see 120 29 37 10 196 
Calculatede-ccqeaea ee eee 110 37 Si iP 196 
PithereMnce Weak. es ees +10 —8 0 —2 0 
Purple Ia x brown V.— Crosses of brown with purple gave purple ~ 
F,’s, and four Fs progenies gave a total of 116 purple and 38 brown plants, 
which is very near the 3:1 ratio expected from F, plants of the genotype 
AaBB PI Pl, the deviation being 0.5 + 3.6. Nine F,; purples backcrossed 
to browns gave progenies totaling 484 purple and 477 brown plants, a 
deviation from the expected equality of 3.5 + 10.5. 
Purple Ia x sun red IITa— Purples and sun reds should differ by a 
single factor pair, Pl pl. The F; purples backcrossed to sun red should 
give a 1:1 ratio of the parental types. Five such backcrosses gave 47 
purple and 57 sun red plants, a deviation from expectation of 5 + 3.4. 
No progenies of selfed F;’s were observed. 
Purple Ia x dilute purple I[[a.— Purples are assumed to differ from 
dilute purples by the factor pair Bb. Six Fi purples backcrossed with 
dilute purple gave 40 purple and 52 dilute purple plants. This is a 
deviation from the expected equality of 6 + 3.2. No other tests of the 
cross of purple x dilute purple were made. 
Sun red IIa x dilute sun red IVa.—- Sun reds and dilute sun reds should 
differ in one factor pair, B b, and should therefore give a simple 3:1 result 
in F,. The F; generation of six crosses of these color types consisted 
of 135 sun red plants. Sixteen F2 progenies listed in group 1 of table 24 
