Aug. 18, 1923 
Inheritance of Dwarfing in Maize 
2 .99 
crosses between variations somewhat similar in appearance result in the 
restoration of the normal form, these two dwarfs are so strikingly alike 
in the characteristic of reduced internode length that F x plants of nor¬ 
mal stature were not anticipated. 
That the combination of these two dwarf forms should restore com¬ 
pletely tall stature furnishes an impressive example of the potential 
hereditary possibilities resident in abnormal variations and demon¬ 
strates the futility of predicting the hereditary behavior of defects 
which appear similar. 
SECOND GENERATION 
The distribution to be expected in the second hybrid generation of such 
a cross, assuming that the two characters are unrelated genetically, is 
nine normal, three brachytic, three dwarf, and one representing a com¬ 
bination of the dwarf and brachytic forms, the physical characteristics of 
which can not be predicted from those of the parents. Six rather large 
progenies were grown, but no group representing the combination of the 
brachytic and dwarf variation was recognized. The classification of 
plants is given in Table I. 
Table I .—Showing the number and percentages of the three types of plants obtained in 
the second generation of the dwarf-brachytic hybrid 
Progeny. 
Number of— 
Percentage of— 
Nor- ' 
mal. 
Brachy¬ 
tic. 
Dwarf. 
Total. 
Brachytic. 
Dwarf. 
Dh 444 Li R21. 
I 123 
45 
36 
204 
22. I ±2. OO 
17. 6del. 8 
L2 R21. 
107 
39 
17 
163 
23.9 ±1.90 
10. 4±i. 6 
L3 R21. 
140 
60 
28 
228 
26. 3 ±2. OO 
12.31b 1. 5 
L4 R21. 
*45 
45 
6 
196 
23. 0 ±1.90 
3 -i± -8 
Ls R21 . 
143 
40 
8 
191 
20 . 9 ± 2 . OO 
4. 2 ± 1. 0 
Li R22. 
560 
172 
192 
924 
18. 6 dh . 27 
20. S± . 3 
Total. 
1, 218 
401 
t-. 
00 
cs 
1, 906 
21. o4± . 20 
IS-1± • 17 
The first five progenies were grown at Arlington, Va., in 1921, and the 
sixth at the same place in 1922. Unusual care was exercised in 1922, 
and both soil and weather conditions were much more favorable for the 
survival of dwarf plants than they were in 1921. In the discussion to 
follow only plants raised in 1922 are considered. 
Subsequent breeding experiments with self-pollinated brachytic plants 
from these segregating F 2 progenies have shown that the combination of 
the two variations resembles dwarf plants very closely, being somewhat 
smaller perhaps, though not strikingly so, and having the accompanying 
characteristics such as perfect flowered ears, etc. (PI. 4). In this respect 
the double recessive form of brachytic-dwarf differs markedly from that 
found by Emerson in the cross between dwarf and anther ear, where a 
strikingly small and rather easily identified sterile double recessive was 
isolated in the second generation. 
Sixteen F 3 progenies were grown from self-pollinated seed of brachytic 
segregates in the F 2 populations of 1921. Of these, just half proved to be 
heterozygous for dwarf, these dwarf plants representing the double 
