THE ANCESTOR OF CORN—-MANGELSDORF 499 
pared the diagrammatical, longitudinal section illustrated in figure 2. 
The tiny kernels which this cob must once have borne could only 
be those of popcorn, a type in which the kernels are small and hard 
and capable of exploding when exposed to heat. The long stems or 
pedicels on which the kernels were borne and the long floral bracts 
which almost completely enclosed them show that the Bat Cave corn 
was also a form of pod corn, a type in which the individual kernels 
are enclosed in pods or chaff. 
It is interesting to note in this connection that the late E. Lewis 
Sturtevant, a longtime student of corn, concluded many years ago 
that both popcorn and pod corn are primitive. My former colleague 
R. G. Reeves and I [6] later reached a similar conclusion. The an- 
cient Bat Cave specimens provide convincing archeological evidence 
in support of these conclusions. 
CROSSING PRIMITIVE CORNS 
What we have done, then, is to cross a number of varieties of pop- 
corn from various parts of the world with pod corn (pl. 3, fig. 2), 
which still occurs as a “rogue” or “freak” in some South American 
varieties and which in some localities is preserved by the Indians, who 
believe it to have magical properties. Pod corn has also sometimes 
been grown in gardens in the United States as a curiosity. Today it 
is most likely to be found in the experimental cultures of corn geneti- 
cists, who maintain it as one of the “marker” genes on the fourth long- 
est chromosome of corn. 
There is no doubt that pod corn is primitive in its characteristic of 
enclosing the kernel in glumes or chaff, as do all other cereals and 
virtually all other grasses. Despite this fact, and because it is often 
monstrous and sometimes sterile, it has been dismissed by a number of 
botanists from any role in the ancestry of corn [7]. We believe that 
its monstrousness has been misunderstood—that pod corn is monstrous 
today only because it is a “wild” relict character superimposed upon 
modern highly domesticated varieties. 'Today’s pod corn is compa- 
rable to a 1900 chassis powered by the engine of a 1958 car. The sur- 
prising thing is not that pod corn is sometimes monstrous but that it 
is not more so—that the particular genic locus which governs its ex- 
pression is capable of functioning at all in a milieu so different from 
that in which it was undoubtedly well adapted. We have assumed 
that pod corn would be less monstrous and would exhibit normal grass 
characteristics when combined with other “wild” genes, and we hoped 
to find these in varieties of popcorn. 
Our hopes have been realized. Popcorns in general tend to reduce 
the monstrosity of pod corn when crossed with it, and some varieties 
do so quite drastically. The varieties Lady Finger and Argentine 
