1100 
Journal of Agricultural Research 
Vol. XXVIII, No. 11 
Table II.— Coefficients of correlation among the characters of the plants of the F\ 
of Jala X Tom Thumb a 
Character designation 
Height 
Leaves 
above 
ear 
Days to 
silk 
Pollen to 
silk 
Weight 
of seed 
Length 
of ear 
Number 
of rows 
Diameter 
of 
stalk 
Height__ 
0. 26 
0. 23 
0.18 
0.12 
0.28 
0.16 
0.14 
Leaves above ear. 
0. 26 
. 13 
.05 
-.07 
. 16 
.22 
.00 
Days to silk. 
.23 
. 13 
. 02 
—.23 
.07 
. 12 
—. 05 
Pollen to silk_ 
. 18 
.05 
.02 
.10 
.05 
.26 
-.00 
Weight of seed. 
. 12 
—.07 
-.23 
. 16 
.37 
. 11 
.03 
Length of ear. 
.28 
. 16 
.07 
.05 
.37 
.43 
. 11 
Number of rows. 
. 16 
.22 
. 12 
. 26 
. 11 
.43 
.07 
Diameter of stalk_ 
. 14 
.00 
-.05 
-.00 
.03 
. 11 
.07 
o Coefficients in excess of 0.272 are greater than 3 times their error. 
From these Fi coefficients the conclusion seems justified that physiologica 
correlations are not important within the ranges of the characters studied, but 
the ranges involved in the Fi are in no case extreme. 
Proceeding to the correlations among the characters of the second generation, 
it will be seen from an examination of Table III that the closest correlations are 
with height of plant. Curiously enough, the correlation of plant height with 
length of season, as measured by the number of days to silk, is not high, though 
the plants of the second generation ranged from 4 to 33 decimeters in height and 
required from 62 to 102 days to silk. 
The length of season or days to silk is also correlated with the weight of the 
seed and with the length of the ear, but since the height of the plant is rather 
closely correlated with ear length, it may be urged that the relationship between 
season and ear length is an indirect result of this correlation. Calculating the 
partial correlation for season and length of ear for constant height of plant, it is 
found that though the relationship between ear length and season is reduced 
to .131 the correlation remains significant. Treating the correlation between 
season and weight of seed in the same manner, the partial correlation for constant 
height becomes .096 or negligible. 
Table III.— Coefficients of correlations among the characters of the plants of the F 2 
of Jala X Tom Thumb a 
Character designations 
! 
Height 
Num¬ 
ber of 
leaves 
above 
ear 
Height... 
! 
0.107 
Number of leaves above ear.j 
0.107 
Number of days to silk.1 
.174 
.089 
Number of days from pollen to silk_ 
.044 
.097 
Weight of seed...i 
.350 
.062 
Length of ear..i 
.457 
.108 
Number of rows__ 
.025 
. 162 
Diameter of stalk ... 
.568 
.098 
Num¬ 
ber of 
days 
to silk 
Num¬ 
ber of 
days 
from 
pollen 
to silk 
Weight 
of seed 
Length 
of ear 
1 
| 
Num¬ 
ber of 
rows 
Diame¬ 
ter 
of stalk 
0.174 
0.044 
0.350 
0.457 
0.025 
0.568 
.089 
.097 
.062 
.108 
.162 
.098 
.338 
.149 
.194 
—.093 
.107 
.338 
.105 
.071 
—.027 
.065 
. 149 
.105 
.382 
—.087 
.290 
. 194 
.071 
.382 
.084 
.380 
—.093 
—.027 
—.087 
.084 ! 
.039 
.107 
.065 
.290 
.380 j 
.039 
a Coefficients in excess of 0.119 are greater than 3 times their error. 
From a consideration of the correlations with days to silk there would seem to be 
no great obstacle to combining earliness with large ears, heavy seeds, or even tall 
plants. On the other hand, more difficulty would be encountered in attempting 
a combination of short plants with long ears and heavy seeds or in producing 
stocky plants by combining short stature with large diameter. 
