A BRACHYTIC VARIATION IN MAIZE. 21 
ears were found with staminate spikes ranging from 15 cm. in 
length to those with just a few scattered spikelets near the tip or 
with only a disorganized area where spikelets failed to develop, 
leaving a bent and deformed ear. The range of variation in the 
Boone-brachytic hybrids is shown in Plates XV and XVI. 
The variation is one which is found frequently in maize in several 
forms. The nature of its inheritance has not been reported, but 
that it is heritable seems certain. 
While neither the Boone nor the brachytic parent plants produced 
ears with staminate spikes, many plants of the first generation pro- 
duced such ears. The exact ratio in the F x was 17 with staminate 
tips to 63 normal. This is a very close approximation to a Men- 
delian monohybrid ratio, where the variation is recessive to the 
normal form of the ear. To secure such a ratio in an F 19 it may be 
assumed that both parents were heterozygous for the character in- 
volved. The same result would be obtained if normal ear form were 
the result of two dominant independent factors with the br achytic 
parent heterozygous for both of these factors and the Boone parent 
homozygous for one dominant factor and heterozygous for the other. 
On this latter hypothesis the progeny of the self-pollinated brachytic 
parent would have 43.75 per cent of the plants bearing ears terminat- 
ing in staminate spikes, while the self -pollinated Boone parent would 
give 25 per cent of the progeny with such ears. 
Of the nine hand-pollinated ears obtained from brachytic plants, 
six were the result of self-pollination, the other three representing 
crosses between sister plants. Only one progeny grown from these 
nine ears exhibited the staminate spike character. This progeny 
was from a self-pollinated ear. Ears were produced by 36 plants, 20 
of which had staminate spikes that ranged in length from 2 to 12 cm. 
The average length was 6.55 ± 0.52 cm. The percentage of plants 
having staminate spikes (55.5±5.6) is very close to that for a 
Mendelian dihybrid, Avhere the character is the result of the com- 
bination of two dominant factors and the parent plant is heterozy- 
gous for both of them. As in all the second-generation progenies in 
which this character reappeared it behaved as a recessive character, 
the percentage of 55.5 may be considered a chance departure from 
43.75. With the small number involved (only 36), the deviation of 
11.75 per cent above the 43.75 is less than three times the probable 
error. 
If the above explanation is correct, self -pollinated F x plants should 
give the following progenies : One all normal, three with 25 per cent 
of the plants with staminate spikes, two with 43.75 per cent of the 
plants with staminate spikes, and two with all the plants with stami- 
nate spikes. The last two, of course, would be recognized in the first 
