314 WEATHERWAX: THE EVOLUTION OF MAIZE 
case, where the spikelets are paired, the pedicelled ones are ar- 
ranged symmetrically in a horizontal plane along the sides of the 
lateral rachis, and the sessile ones are ventral to these on the 
rachis, giving the structure a definite dorsoventral aspect (Fic. 
5). The central spike is symmetrical with respect to the pairs 
of spikelets, which are arranged in several longitudinal rows upon 
it (Fic. 3). 
The spikelets have been described in detail elsewhere (25, 26). 
Each has two flowers and a full complement of glumes, palets, 
and lodicules. Only the male essentials are functional, but each 
flower has a rudimentary pistil. A superabundance of pollen is 
produced, and it depends upon gravity and the wind for distribu- 
tion. The flowering period of an individual plant is limited to 
two or three weeks, depending upon weather conditions and the 
size of the inflorescence. 
Female inflorescence-—The ear- 
bearing branch has the same gen- 
eral structure as the main stalk, 
except that its inflorescence is fe- 
male; and the shortness of its axis 
enables the leaf sheaths to cover 
the inflorescence and mature fruit. 
In some cases the laminae and 
ligules of these prophylla are pres- 
ent (Fic. 6), but often they are 
each prophyllum is a bud which 
may develop into an ear-bearing 
shoot (Fic. 8). This behavior is 
common to some varieties, and it 
seems possible to bring it about in 
any variety by subjecting the plant 
Fic. 6. An ear of corn whose 
teak idee Milnes: to proper physiological conditions. 
The clusters of ears formed in this 
way and occurring in ordinary maize (6, f. 96, 97) or in teosinte- 
maize hybrids (17, pl. 1) are not at all to be confused with branched 
ears of maize (Fic. 9). They have much the same appearance to 
the casual observer, but they have a different origin and a different 
