A BRACHYTIC VARIATION IN MAIZE. 25 
usual position are found. The intermediate stages between these 
well-formed ears and branches which have only a few pistillate 
flowers at the base closely resemble the ears that terminate in stami- 
nate spikes. 
The pistillate branches, or ears, are clustered around the base of 
the tassel, the internodes being so short as to be indistinguishable 
from one another. (See PI. XVII.) The transformation from male 
branches to ears is accomplished by a shortening of the rachis which 
is first noticeable at the base of the branch. In the advanced stages 
this shortening results in a crowding of the spikelets, which fre- 
quently is augmented further by a zigzagging of the rachis. In these 
cases there often is evidence of twisting. The spikelets in the early 
stages of the transformation of the branches are little altered, but 
with the added shortening of the rachis the glumes become reduced 
in length and gradually assume the characteristics of glumes on 
normal ears (Pis. XVIII and XIX). 
While the tendency to have ears clustered at the base of the tassel 
is found on plants with normal internodes as well as on brachytic 
plants, the nature of the transformation from staminate to pistillate 
branches strongly suggests brachysm. Thus, there is an abrupt short- 
ening of the main axis at the point where the branching occurs and 
also a marked shortening of the rachis of the branches, accom- 
panied by a development of pistillate flowers. These changes are 
essentially those which took place in the development of the normal 
ear and are similar to those indicated in the brachytic plants of the 
Chinese : Algeria hybrid. 
Taken in connection with the fact that half the brachytic plants 
of the Hopi-brachytic hybrid produced ears terminating in staminate 
spikes and that the brachytic plants had but few nodes above the ears, 
the close resemblance of tassel ears to ears in the normal position with 
staminate spikes suggests a possible origin of these staminate spikes. 
Viewed in this light, the ear of maize may have developed not 
from a central spike of the terminal inflorescence of a lateral 
branch but from the transformation of the lower staminate branch 
of the terminal panicle into a pistillate branch. If this hypothesis 
is adopted, the sterile nodes which intervene between the pistillate 
and staminate inflorescences are not so difficult to explain and be- 
come with the ear a part of the terminal inflorescence. 
The lower branches of the tassel occasionally develop into re- 
plicas of normal plants and even more frequently are subtended by 
bracts. These lower branches are relatively unstable, being the 
first to develop pistillate flowers, and the number of rows of spikelets 
often exceeds four. This increase in the number of rows may arise 
through the reduction of secondary branches or perhaps from a zig- 
