WEATHERWAX: THE EVOLUTION OF MAIZE 331 
tions it may be seen that Collins does not necessarily hold to any 
one variety of pod corn for his evidence, switching from earless to 
branched types as he finds structures to fit his hypothesis; and, 
even with this latitude of choice, he fails to find sufficient evidence 
that pod corn is wholly primitive. It is readily granted by any- 
one that the tunicate character and the tendency toward her- 
maphroditism are primitive characters, but otherwise the plant 
is modern, as the fasciated silk, the husks of the ear, and the many 
degenerate organs go to show. The earless plants are the most 
highly specialized of all, as indicated by the vestigial ear-buds in 
the axils of their leaves. 
Similar inconsistencies occur in the description of teosinte, 
which is held to be highly specialized; the mention of a single 
example will be sufficient. In support of a detailed argument 
that the extreme differentiation between the male and female 
inflorescences of teosinte points toward specialization higher than 
that in maize, he says (p. 524) that female flowers have never 
been observed in the male inflorescence of Euchlaena. I have 
already described mixed inflorescences of this plant; but the im- 
portance of this point is diminished by the fact that in this entire 
group of plants we are sone with flowers which are structurally 
bisexual. 
Readily granting that monoecism is a less fixed characteristic 
and that the separation of male and female flowers is not so sharp 
in maize as in teosinte, yet I do not believe that pod corn has been 
shown to be sufficiently different from ordinary corn to merit 
the prominent position that it holds in this theory. 
In a recent report on this theory (11) the intolerance of self- 
pollination in maize is given as another evidence of its hybrid 
‘nature, it being almost if not quite unique among the grasses in 
this respect. But possibly another explanation for this may be 
found in its having a very small number of monoecious inflores- 
cences and, because of protandry or protogyny, a limited chance 
for self-pollination under normal conditions, in which respect it 
is also unique among the grasses. All the other members of the 
Maydeae, teosinte, for example, produce a large number of in- 
florescences and have a flowering period much longer than that 
‘of maize, the chances for self-pollination being correspondingly 
