In spite of the recently discovered evidence for a Mid- 
dle American origin of cultivated maize—one which has 
been favored on the basis of other evidence not only by 
Weatherwax but also by Kempton and Popenoe (21), 
Kuleshov (22), Meade (82), and Vavilov (40)—we are 
not yet ready to rule out completely the possibility of 
an independent center of origin somewhere in South 
America although our earlier idea of a single origin in the 
lowlands of South America has now been abandoned. 
There are still too many facts which are not completely 
explained by the assumption of a single origin in Middle 
America. Among these are: (a) the great diversity of 
corn in the highlands of Peru; (b) the fact that all of 
the known pericarp colors of corn occur in one depart- 
ment, Ancash, of Peru (13); (c) the frequent occurrence 
of pod corn in valleys on the eastern slopes of the Andes; 
(d) the high incidence of the tu” gene in Peruvian corn 
(27); (e) the occurrence in Peru of a primitive race, Con- 
fite Morocho, which could conceivably be the progenitor 
of all of the other known primitive races of the hemi- 
sphere (18). So far as the evidence from living corn vari- 
eties is concerned, it still points strongly to a South 
American center in the highlands of Peru, Bolivia and 
Ecuador and, were it not for the conflicting evidence 
from fossil pollen and archaeological maize, we should 
unhesitatingly continue to assume that corn had its ori- 
gin in South America. 
An obvious solution to this dilemma is to assume that 
maize has been domesticated more than once. Such an 
assumption would not be radically new. We (81) have 
previously pointed out that five of the cultivated plants 
common to Middle America and South America— 
squashes, beans, tomatoes, amaranths, and cotton—were 
represented in the two regions by different species or sub- 
species. There is now evidence that this may have been 
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