388 
Vol. XIV, No. 9 
Journal of Agricultural Research 
The coefficients for average height of culms correlated with average 
length of spikes per plant are 0.315^0.035 in 1914, o.4i9±o.o23 in 1915, 
o.775±o.oio in 1916, and o.668±o.oi7 in 1917. 
Similar to the correlation between yield of kernels and average length 
of spikes, the relation of these two characters has a tendency to be high, 
but is strongly modified by environmental conditions. 
When average height of culms is correlated with total length of spikes 
per plant, the coefficients are o.036±o.o38, o.26o±o.o26, 0.235 ±0.024, 
and 0.351 ±0.027. This is a variation from no correlation to a fairly 
substantial one. The influence of environment may entirely overcome 
the tendency of the two characters to move together. 
Considering as a whole the relation of average height of culms to other 
plant characters, there is a tendency for an increase or decrease in average 
height of culms to be accompanied by an increase or decrease in number 
of kernels and average length of spikes. Between average height of 
culms and average weight of kernels there is a substantial correlation 
and between average height of culms and total length of spikes there is 
a moderate correlation three years out of four. The correlation between 
average height of culms and number of culms is always low. 
CORRELATION OF HEIGHT OF PLANTS AT DIFFERENT STAGES OF DEVEL¬ 
OPMENT 
When height at appearance of second leaf is correlated with height of 
the same plants at six weeks from seeding, the coefficients are 0.406 ± 
0.038 in 1914, o.467±o.022 in 1915, o.47o±o.oi9 in 1916, and o.466± 
0.024 in 1917. The correlation between the two characters is substantial 
and consistent. 
For height of plants at appearance of second leaf correlated with height 
of tallest culm at maturity, the coefficients are o.38o±o.033 in 1914, 
o.270±o.026 in 1915, 0.272±0.023 in 1916, and 0.211 ±0.029 in 1917. 
This is a medium correlation modified considerably by environmental 
influences. 
The coefficients for height at six weeks correlated with height of the 
tallest culms of the same plants at maturity are o.399±o.o38, o.236± 
0.026, o.523±o.oi8, and o.3i4±o.027. The correlation between the two 
characters varies from rather low to moderately high depending upon 
the environment. 
Considering as a whole the correlations between height of plants at 
different stages of development, there is a distinct tendency for plants 
of varying heights at second leaf to maintain the same relative heights 
at six weeks, but there is a lesser tendency for this relation to be main¬ 
tained at maturity. Some of the shorter plants at second leaf approach 
closely or equal in height the taller ones at maturity. There is a tendency, 
considerably modified by environment, for differences in heignt of plants 
at six weeks to be maintained in the tallest culm at maturity. 
