A BRACHYTIC VARIATION IN MAIZE. 
17 
not significant. The frequency distribution for height of plant is 
shown in figure 5. 
In yield, as measured by the total ear length, neither the normal 
nor the brachytic F 2 plants equaled the first generation, but indi- 
vidual plants were obtained which yielded fully as well as the best 
Fig 
5. — Frequency distribution of height of plant in brachytic X Boone, second 
generation. 
of the F x . With a sharp segregation into normal and brachytic 
plants and a failure to increase the variability of height in the segre- 
gated brachytic plants, the procedure to be followed in securing the 
desired combination of brachytic stature with high yield becomes 
greatly simplified and 
eventual success be- 
comes more certain. 
It is necessary only 
to back cross the best 
yielding of the segre- 
gated brachytic plants 
upon the high-yield- 
ing commercial varie- 
ties and repeat the 
procedure until the 
desired combination is 
obtained. 
While the mean 
length of ear of the 
brachytic segregates 
in the second genera- 
tion of the brachytic- 
Boone hybrids is lit- 
tle, if any, greater 
tli an that of the 14 
brachytic progenies, 
several plants were 
obtained which greatly exceeded in length of ear the directly de- 
scended brachytic plants (Pis. XI and XII). The frequency dis- 
tributions for ear length are shown in figure 6. 
The normal plants of the second generation exceed the brachytic 
plants not only in stature but also in the length of the longest leaf, 
to 
20 
10 
0-10 
20 
10 
.A 
A-u 
A 
k~ 
■\A"4 
BOOt\ 
£ 
J 
A 
A 
M 
Km 
&/?/?C 
'HYTt 
C 
J 
<\ 
A*^ 
?18 
?rtCH> 
TIC-L 
>OON£ 
A 
„/* 
r 
a 
V^ 
^~ 
NORM, 
?Lf2 
e^u 
A, 
v^ 
■^ 
/\. A 
BRm 
HYTIi 
! fS 
IO 20 JO 40 SO 60 70 CM 
Fig. 6. — Frequency distribution for total length of ears on 
Boone, brachytic, Boone X brachytic ¥ u and the normal 
and brachytic plants segregated in the brachytic X 
Boone F 2 . 
