A BRACHYTIC VARIATION IN MAIZE. 
A brachytic plant appeared also in a progeny of the Esperanza 
variety of Zea hirta (PL VI). This plant was not self -pollinated, 
but was crossed with a normal plant of the Chinese waxy variety. 
^ 
^ 
s 
OHlLl RLL /VORM/1L 
# /?/vsas oe/rr 9/vo frm/fL /amLSMummm. 
> OHl all norm/il & S 
X ^DH]L3RLL HORMRL 
\OHJL+RLL RORMRL 
PHH2L1ALL W/F/VRt , 
DHJL2L2 RLL HORM/IL \ 
RLL NOR/URL 
RLL MORMRL 
/ILL NORMRL 
/fLL NORMRL 
RLL NORMRL 
RLL RORMRL 
.111 RCR/nRL_ 
RLL NORMAL 
ALL NOR/URL 
ML NOR OWL 
ALL NORMAL 
^v 
LVf/LS NORMAL 
RLL HOR/ARL 
/7LL NORMRL 
RU NORtTRL 
/ILL a/ormal 
ALL NORMAL 
RLL NOR/ltRL 
ALL /VORMAL 
/ILL NORMRL 
ALL NORMAL 
/ILL NORMAL 
RLL NORMRL 
f)LL NORMRL 
RLL NORMRL 
RL L NORMRL 
RLL NORMRL 
Fig. 1. — Pedigree chart of a brachytic strain which does not breed true. None of the 
progenies shown in this chart were the result of self-pollination except DhlL16, the 
progeny of a brachytic plant. 
The hybrid has been designated Mh 17 by Collins (1). The first- 
generation plants were all much taller than either parent. Three 
plants were hand-pollinated, but not selfed. The second-generation 
progeny of these plants gave no evidence of brachysm, as is shown 
by the frequency distribution for plant height (fig. 2). The modal 
height of the second-generation plants was 190, which is the aver- 
age height of normal Es- 
peranza plants. The bra- 
chytic Esperanza parent 
of this hybrid was 105 
cm., while the Chinese 
parent was but 167 cm. 
high. Succeeding gen- 
erations have continued 
normal in stature, al- 
though progenies differ- 
ing widely in height have 
been isolated. It is hoped 
that crosses between some of these progenies and) true-breeding 
brachytic strains will explain the complete disappearance of this 
variation in the Mh IT hybrid. 
200 20 +0 
Fig. 2. — Frequency distributions of height of plant 
of the first and second generation hybrid between 
the brachytic Esperanza plant shown in Plate VI 
and a Chinese waxy plant of normal stature. 
