During this same period, the theory has also been the 
object of lively controversy and of strong objections. On 
this hundredth anniversary of the publication of Darwin's 
**On the Origin of Species’’ and the twentieth anniver- 
sary of our own more modest contribution, it seems ap- 
propriate to take a broad new look at the entire problem 
of the origin of corn —a problem which not only is fas- 
cinating in its own right, but one whose solution prom- 
ises to shed some light on the evolution of other culti- 
vated species. It is our purpose, then, to evaluate both 
the old and the new evidence as well as the objections; 
to consider the various theories which have been pro- 
posed; and to review the extensive relevant literature 
which has appeared in the last two decades. 
In discussing theories on the origin and evolution of 
maize, it is perhaps inevitable that we should give major 
attention to our own. There is nothing unusual in this 
situation. Most new theories, if they are taken seriously 
at all, have strong objections raised against them. It is 
one of the obligations of their authors to give serious 
consideration to these objections and to answer them if 
possible, since if they fail to do so, it may erroneously 
be assumed that the theory has been disproved. If the 
objections cannot be answered in a logical and plausible 
way with the facts at hand, then either the theory is weak 
and requires modification or more evidence is needed. In 
either case, the free exchange of opinions, although sel- 
dom completely objective on either side, can serve a use- 
ful purpose. Controversy — up to a point — can some- 
times be as useful as research in clarifying a problem. 
GENERAL CONSIDERATIONS 
Most of the objections to our tripartite theory of the 
origin of maize are directed specifically at one of its three 
parts, but some are of a more general nature. These are 
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