‘T'ripsacum and could therefore be dismissed as the ances- 
tor of corn. Pod corn, then, appeared to be the only 
plausible alternative to teosinte as the progenitor, unless 
we resorted, as have several of our critics, to a strictly 
hypothetical ancestral form which is now extinct. 
The strongest objections to the pod-corn theory have 
come from Weatherwax (29, 80,31). They fall into seven 
principal categories: (A) Pod corn is ‘‘equivocal,”’ a 
word of many meanings, which when used in this particu- 
lar context, seems to be more or less synonymous with 
‘extremely variable.’’ (3) It is monstrous and sterile. 
(C) It is similar to other monstrosities like teopod and 
corn grass. (1)) It does not have the characteristics of a 
wild grass. (KE) It could not have existed in the wild. 
(F) It is the product of plant hormone action. (G) The 
weaker form of pod corn, ‘‘half tunicate,’” which at first 
glance seems to be a more promising ancestral form, af- 
fects only the glumes and does not influence the other 
characteristics of the plant. Let us examine these objec- 
tions separately. 
(A). The first objection is fallacious in two respects: 
(x) The character, although often variable, is little, if 
any, more so than other characteristics of the corn plant, 
such as monoecism and the ear itself—two features which 
distinguish corn from all other important cereals. If, in 
attempting to reconstruct the ancestral form, we are to 
rule out all characters of the corn plant which are highly 
rariable, we can do little more than say that it was a 
grass, a fact on which all students of the subject have so 
far been in remarkable agreement. (b) Pod corn actually 
is not at all equivocal when the genetic background and 
environment are held constant. Through repeated back- 
crossing, we have transferred both the Zw and the tu’ 
genes to two inbred strains, A158 and P89. Although 
the different genotypes which can be produced with the 
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