34 
BULLETIN 1164, U. S. DEPARTMENT OF AGRICULTURE. 
The highest and the lowest F 3 progeny mean differed very signifi- 
cantly for every character, the difference having amounted to 12 to 50 
times its probable error. These data point strongly to the conclusion 
that segregation had taken place in F 2 . 
For 11 of the 18 characters the highest F 3 mean was either higher 
than or did not differ significantly from that of the parental popula- 
tion which gave the higher mean, while for the other 7 characters the 
highest F 3 mean was significantly lower than the higher parental 
mean. For 14 of the 18 characters the lowest F 3 mean was either 
lower than or did not differ significantly from that of the parental 
population which gave the lower mean, while for the other 4 charac- 
ters the lowest F 3 mean was significantly higher than the lower 
parental mean. 
Table 8. — Means for 18 characters of the F 3 hybrid progenies having, respectively , the 
highest and the lowest mean and means of the parental populations of Pima and 
Holdon cotton. 
Character. 
Axis: 
Length 201. 5±2. 
Internode number 45. 9± 
Internode length 45. 0± 
Fruiting branch: 
Length 50.9±1. 
Length, first internode 19. 5± 
Leaf- 
Length 1 63. 9 ± 4. 
Width 204. 1 ±6. 
Index j 139. 5±1. 
Lobe index [ 56. 0± . 
Vein angle ! 107. 0±1. 
Hybrid F 3 (1920). 
Highest 
mean. 
Callus color. 
Petiole hairiness.. 
Petal: 
Color 
Spot 
Boll: 
Length 
Diameter 
Index 
Lock number. 
7.9± 
6.6± 
3.8± . 
6.6± , 
40. 4± . 
28. 4± , 
85.6±1. 
3.9± . 
Lowest 
mean. 
6S.2±4.62 
26. 5± .87 
25.3±1.G9 
i21.8±1.91 
i6.3± .68 
92.9±2.31 
116.5±1.C6 
107.4±1.97 
30. 5± .97 
72.6±2.11 
2.2± .08 
1.1± .03 
1.2± .04 
± 
21. 7± .89 
16. 3± .49 
65.7±1.21 
3.1± .01 
Differ- 
ence 
divided 
by its 
probable 
error. 
24.4 
19.7 
15.5 
12.3 
14.0 
13.9 
12.9 
13.4 
18.7 
14.0 
50.4 
48.3 
36.1 
34.7 
15.6 
21.4 
12.3 
25.3 
Tarental (1919). 
Pima 
Holdon. 
184.0±4.16 
39. 0± .30 
47. 1± .70 
72. 2± 1.56 
19. 0± .60 
92.0±2.20 
26. 2± .71 
35. 6± .85 
21.3±1.06 
2.1± .14 
182.0±1.91 127.0±l.t„ 
236.0±4.90 ! 143.0±4.10 
130.0±2.30 
36. 1± .61 
103.4±2.14 
2.1± .02 
1.0±0 
5.0±0 
6.5± .19 
47. 5± .41 
27. 6± .13 
58. 2± .49 
3.0± .01 
113.0±2.80 
45. 9± .75 
94.5±1.10 
6.7± .06 
5.2± .08 
1.0±0 
±0 
45. 1± .42 
38. 2± .23 
84. 7± .70 
4.4± .01 
1 Progeny No. 140, on which these characters were not measured, was of the extreme cluster type and 
would doubtless have given lower values. 
PARENT-OFFSPRING CORRELATIONS OF F 2 AND F 3 . 
The coefficients of correlation between the means of the F 3 prog- 
enies and the values of the F 2 parents of these progenies, computed 
for all characters determined in F 3 , are given in Table 9. The average 
of the coefficients of correlation for the 17 characters which did not 
show segregation in definite ratios in F 2 is 0.66. That for leaf width 
is only 2.8 times its probable error, but for all other characters the 
coefficient is not less than 4 times its probable error. This criterion, 
therefore, } T ields additional evidence that segregation had taken place 
inF,. 
