theory that maize originated from teosinte under domes- 
tication can now be safely ruled out. 
Recent studies of archaeological maize, like those of 
fossil pollen, do not support the teosinte theory. On the 
contrary, they show that the earliest maize was less like 
teosinte, whereas some recent maize is more like it. 
Archaeological specimens exhibiting characteristics of 
teosinte, including distichous ears, single spikelets and 
highly lignified rachises and glumes, have been found in 
several sites. But these are always recent specimens and 
are interpreted as being products of the introgression of 
teosinte into cultivated maize (7, 11, 19, 20, 25). 
A series of studies on the morphology of the corn ear 
has a bearing on the teosinte theory, because many work- 
ers who favored this theory explained the polystichous 
character of the corn ear as the result of the lateral fusion 
of several teosinte spikes. The voluminous literature on 
this subject was reviewed by Mangelsdorf and Reeves 
in 1939 (21) and more recently by Nickerson (27). The 
present status of the problem is that evidence for the 
lateral fusion of two-rowed spikes to form the polysti- 
chous ear is completely lacking; the only evidence found 
for fusion is the adnation of the rachis flaps (prophylls) 
to the main axis of the cob. It may be concluded, there- 
fore, that the structure of the corn ear has thus far shown 
no evidence that corn is a descendant of teosinte. 
THe ‘THeory or COMMON ANCESTRY 
It appears that Montgomery (26) was the first to pro- 
pose the theory of common ancestry, although he did 
not include Tripsacum in the alliance with corn and teo- 
sinte. Weatherwax (87) formulated the theory as we 
now know it, by adding Tripsacum to the two species 
considered by Montgomery, and he defended it in sub- 
sequent publications (88, 40, 41, 42). Randolph (28, 29) 
[ 433 ] 
