AN ANALYSIS OF THE EFFECT OF SELECTION. 
TasBie 17.—Inbred Plus Lines Crossed. 
Generation. n M o ip 
1 Vere eee ea 192 | 5.365+0.041 | 0.824+0.029 |................. 
ges. siskees are 689 | 5.374 .022 mea dae rc OLD lla rcraye severe cla cleretterar ots 
1941 Ser ALONE. 
isieyevstrajeher arate 42 | 5.500+0.080 | 0.764+0.056 
Wate watetasiete se 279 | 5.233+ .034 .843+ .024 | 1—0.278+0.044 
Total 605 | 5.783+ .018 .666+ .013 — .0386+ .027 
F; 4 Plus 395 | 5.767+ .023 AAS ME OIG) Eiger ene OSCR 
Minus 210 | 5.814 .031 GLO Sar OZZMIN cits: crave cocie tee ale ot te 
Total 303 | 6.116+ .020 .5383+ .014 + .131+ .038 
Fy 4 Plus 270 | 6.144+ .022 POLO == NOLS. cinvsncrsvaycis) tessa skevere is 
Minus 33 | 5.879+ .069 {D887 OF0N le neta noaieee ore 
1,789 
es 
1 Does not include culture 2054, in which the mother was not-Dichet. 
11 
i } 
Fic. 10.—Means and standard deviations for cross of two inbred plus lines. 
Fic. 11.—Means and standard deviations for cross of 1002 inbred plus 
and speck (1331) minus lines. 
21 
was nearly the same as that in F,, the F,-F; and F;—F, parent-offspring 
correlations were not significantly different from 0, and the means of 
the plus and minus selected series in F; and F; were practically identi- 
eal. This constitutes practically a proof that the two lines did not 
differ with respect to modifying genes. 
is by no means highly improbable on the multiple-factor view. 
The result, while surprising, 
The 
