34 R. A. EmMrErson 
crossed with the triple recessive green, type VIc. The records of these 
crosses, seven in all, are presented in table 6. The results are, as expected, 
in close agreement with the backcross data from the cross of purple with 
green. The comparison below indicates a good fit of calculated to observed 
frequencies for the lot as a whole. The probability that such deviations 
as are observed may be due to mere chance is about 0.82, indicating that 
as great departures from expectation as these might be expected about 
four times in five trials. The comparison follows: 
Dilute Dilute 
purple sun red 
la ita} Illa IVa VS Vilessie 
Color types Purple Sun red Brown Green Total 
Observed..... 84 72 78 72 79 249 634 
Calculated.... 79 79 79 79 79 237 632 
Difference. ... +5 —7 —1 —7 0 +12 +2 
Backcrosses of Ia x VIc and IVa x V with IVa 
Purple plants of F; of the crosses purple x green and dilute sun red x 
brown were crossed with homozygous dilute sun red stocks. On the 
basis of the hypothesis used above, the F; plants are assumed to be A a 
Bb Pl pl and the dilute sun red plants A Abbpl pl. Four classes of 
plants, purple, sun red, dilute purple, and dilute sun red, should be pro- 
duced in equal numbers by this cross. The data are presented in table 7 
(page 125). Progenies of F; plants from the cross purple x green are listed 
in group 1 and those from the cross dilute sun red x brown in group 2. 
As will be seen from the comparison below, the observed numbers are in 
fair agreement with the hypothesis. The probability that such deviations 
as occur may be due to chance is approximately 0.67. In other words, 
there are two chances in three that deviations of this sort are due to 
errors of random sampling alone. The comparison follows: 
Dilute Dilute 
Color types Purple Sun red purples ene Total 
la Ila IIIa IVa 
Observed ase ye ees 299 270 288 291 1,148 
Galeulatedh 3-2 ieee 287 287 287 287 1 ,148 
Witerence. a) ee ee +12 —17 +1] +4 0 
