CHARACTERS IX AX UPLAND-EGYPTIAN COTTON HYBRID. 
17 
F, distributions for 37 of the 39 characters comprise the means of 
both parental populations and for 33 characters they extend to or 
beyond the extremes of both parental populations. For 10 charac- 
ters the F 2 range extends in both direction- beyond the combined 
range of "the Holdon and Pima populations. For the chara 
bract connation index, bract number of teeth, and midlock furrow 
! 
1 
// 
/ 
55 
s^ 
IS 
// 
Fig. 7. —Fruiting branch, first internode length: 
Frequency distribution of Holdon X Pima 
Fj cotton'plants, by grades, as used in com- 
puting the correlations. The ordinate fig- 
ures indicate the number of plants a 
centage of the total population. 
Fig. v— Leaf length: Frequency distribution of 
Holdon X Pima Fc cotton plants, by grades, 
as used in computing the correlations. T In- 
ordinate figures indicate the number of plants 
as a percentage of the total population. 
index half or more of the F 2 range lies outside the combined parental 
range. v 
On the other hand, the extreme range for six characters of one of 
the parental populations — in every case the Holdon population — was 
not fully recovered in F 2 . These characters are axis internode num- 
ber, corolla length, corolla index, anther color, boll diameter. 15 and 
boll lock number. 10 
so 
/23-^s-srQS 
I 
k 
y 
20 
/o 
o 
/ 
f 
/=> 
A 
=• 
/ 
Fig. 9.— Leaf width: tiequency distribution of 
Holdon x Pima Fj cotton plants, by grades. 
a« used in computing the correlations. The 
ordinate figures indicate the number of plants 
as a percentage of the total population. 
Fig. 10.— Leaf index: Frequency distribution of 
Holdon x Pima Fj cotton plant-, 
as used in computing the correlations. The or- 
dinate figures indicate the number of pi. 
a percentage of the total population. 
The frequency distributions in two cases show an extreme 
expression in F 2 of characters which are but slightly expressed in 
either parent variety. These are pronounced connation of the 
ills (J, p. 262) states that in a cross of the Russell variety of upland cotton with an Egyptian vari- 
ety ''the characteristically fat Russell boll did not \actlv among 60 Fi plants."' 
•'"An Egyptian-upland cotton hybrid is described by Balls ;. 164) in which the mean lock 
number of the upland parent was considerably exceed) d in Fj. 
42433—23- 
