A BRACHYTIC VARIATION IN MAIZE. 3 
ties (No. Dh 416). The second generation, in which the brachytic 
plants appeared, was the result of self-pollinating a first-generation 
plant which was being grown for seed characters (10). Approxi- 
mately one-quarter of the plants were brachytic, the actual numbers 
being 5 brachytic and 21 normal (11). 
The appearance of brachytic plants in the second generation of 
this hybrid may be explained by assuming that the Chinese parent 
was heterozygous for brachysm. The reasons for this assumption 
will appear later. On this hypothesis one-half of the Y 1 plants 
when self-pollinated should give progenies having one-quarter of 
the plants brachytic, and if the Chinese parent had been self- 
pollinated, one-quarter of its progeny also should be brachytic. 
The Chinese plant, unfortunately, was not self-pollinated, so that 
the possibility of its having been heterozygous for brachytic culms 
can not be tested directly. However, many hundred progenies and 
several large bulk plantings of this waxy variety have been grown 
without brachytic plants having been found. It would seem, there- 
fore, not unreasonable to conclude that this variation is the result 
of a relatively recent genetic change and is not the result of bringing 
into expression a recessive variation which has been masked by the 
dominance of normal culms. 
The brachytic plants might also be accounted for by assuming that a 
single gamete of the Chinese parent mutated and was fertilized by 
a normal gamete of the Algerian variety, but since only three second 
generation progenies of the hybrid Dh 416 have been grown, there is 
a possibilit}^ that more than one gamete of the Chinese parent of this 
hybrid had mutated. 
One of the brachytic plants was self -pollinated and the resulting 
progeny Avere all brachytic. At the present time 16 progenies, de- 
rived from self-pollination or crosses between sister brachytic plants, 
have been grown. These progenies without exception have produced 
nothing but brachytic plants. 
In addition to these 16 progenies several crosses have been made 
between plants of normal stature and brachytic plants. The first 
generations of such crosses were all as tall as or taller than the normal 
parent, while the second generations show a segregation into normal 
and brachytic plants closely approximating the Mendelian 3 to 1 
ratio. 
Both parents of the hybrid from which the brachytic plants arose 
may be considered of the pop-corn type and bear several small ears. 
The brachytic plants are in no sense inferior to their parents in leaf 
area or yield of grain. A comparison of normal and brachytic 
progenies is shown in Table I. These progenies were grown from 
self -pollinated ears of sister plants. 
