56 R. A. Emerson 
a total of 28 purple and 29 dilute purple plants. The parents are therefore 
assumed to have been AA Bbplpl and A Abb Pl Pl, tho the same 
results should have been obtained if one or the other, but not both, 
of the parents had been Aa. The important point here is that purple 
plants were produced in all crosses, showing that sun red and dilute purple 
carry complementary factors for purple. The factors are assumed, in 
keeping with the hypothesis under test, to be B and PI. 
In accordance with this hypothesis, the F; purple plants should be 
AABb Plpl and shouid throw four color types in Fs. No direct Fe 
progenies have been observed, but seven progenies from backcrosses 
of F; purples with dilute sun reds are recorded in table 28. While the 
deviations from the expected equality among the four classes are rather 
large, they are not greater than might occur by chance about once in 
four trials, P equaling 0.26. The comparison follows: 
; Dilute Dilute 
Color types Purple Sun red purple annie Total 
la Ila Illa IVa 
@bserved 2s See ae 99 110 104 83 396 
Calculatedor i i ie 99 99 99 99 396 
Ditlerence os | he ee ee 0 +11 +5 —16 0 
Purple Ia x dilute sun red [Va.— Crosses of purple with dilute sun red 
should give purple F; plants, A A Bb Pl pl, and 9:3:3:1 F.2 progenies. 
Four such crosses resulted in 65 purple plants in F,. The Fs. results are 
reported in table 29, group 1. The distribution of the individuals of the 
twenty-six progenies taken together is shown below in comparison with 
the calculated distribution. The four color types expected were observed 
in approximately the expected numbers. Deviations such as shown might 
be expected thru chance about twice in eleven times, P equaling 0.18. 
Dilute Dilute 
Color types Purple Sun red purple: Saeed Total 
Ta Ila Illa IVa 
Olosery cde) ee a eae 1,013 316 296 100 25 
@alculated ent ae con 970 323 323 108 1 724 
IDitierencen ae ee ee +43 —7 —27 —s +1 
