three alleles at this locus are very different in the two in- 
breds and their hybrids, there is little if any more varia- 
tion within the genotype than there is in nontunicate ears 
of these same inbred strains. The uniformity within any 
one genotype, when the alleles at the pod-corn locus are 
incorporated into a uniform genetic background, proves 
that the variability of pod corn — what has been called 
its ‘‘equivocal’’ nature — is primarily a matter of varia- 
tion in the genetic background. What we see in any ear 
or plant of pod corn is the product not only of the 7’ 
or tu’ gene but of these genes interacting with all other 
genes. 
(B). The interaction of the tunicate gene with other 
genes is an important fact to be remembered in consider- 
ing the second objection, that pod corn is monstrous. 
This objection is not only beside the point, since we 
have always assumed that the ancestor of corn was neces- 
sarily a non-monstrous form of pod corn, but it is also 
not valid. It is, of course, true that modern pod corn is 
often monstrous, especially when homozygous. We be- 
lieve, however, that its monstrousness has been misunder- 
stood; pod corn is monstrous today only because it is a 
wild relict character (a conclusion reached also by Brieger, 
4, 5,6, 7) superimposed upon modern, highly heterozy- 
gous and vigorous varieties, some of them the product of 
teosinte introgression. ‘Today’s pod corn is comparable 
to a 1900 chassis powered by the engine of a 1959 car. 
The surprising thing is not that pod corn is somewhat 
monstrous but that it is not more so—that the particular 
genic locus that governs its expression is capable of func- 
tioning at all ina milieu so different from that in which 
it once served and to 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 the other ‘‘wild’’ genes. Brieger 
[ 885 ] 
