(5, 6) sought these in corn’s relative, teosinte; we hoped 
to find them in varieties of popcorn. ‘This hope has been 
realized as will become apparent later in this paper, when 
the genetic reconstruction of the ancestral form of corn 
is described. 
The sterility of homozygous pod corn, like its gener- 
ally monstrous nature, has evidently also been misunder- 
stood. Weatherwax mentions its ‘‘self-sterility’” — an 
inaccurate term — and states that little, if any, pollen is 
produced and that this is rarely functional. Brieger (5) 
states that the sterility is ‘‘still unexplained.’’ Actually, 
sterility is not an inherent characteristic of pod corn; it 
is, in fact, nothing more than a strictly physiological or 
mechanical effect of overgrown glumes. If the glumes 
are monstrous, the anthers do not reach full develop- 
ment; apparently they do not compete successfully for 
energy with the rampantly-growing glumes. A poten- 
tially sterile tassel of homozygous pod corn can some- 
times be induced to become fertile by the early removal 
of the central spike which is usually massive and bears 
the most monstrous glumes. 
If the glumes are well developed but not particularly 
monstrous, the anthers may develop normally but fail 
to be exserted. Under these conditions, they may shed 
their pollen while still enclosed within the glumes. This 
pollen, which sifts out between the glumes in consider- 
able amounts, is perfectly normal in appearance and is 
quite functional. We have produced a number of pro- 
genies in which all of the plants were of the genotype 
Tutu by collecting such pollen and applying it to the 
silks of normal plants. 
If the glumes are shortened still further by combining 
the Tu gene with appropriate modifiers, then the anthers 
not only develop normally but are also normally exserted. 
We now have strains of homozygous pod corn which 
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