504 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1959 
prominent to match those of the prehistoric specimens—we have suc- 
ceeded in developing what is probably the world’s most unproductive 
corn. This is useful in suggesting that we are on the right track in 
attempting to retrace corn’s evolutionary paths. 
The reconstructed ear illustrated in plate 3, figure 8, has female 
flowers on its lower half and male flowers on the remainder. ‘This, as 
figure 3 shows, is a characteristic of ears borne in a high position on 
the stalk. If our reconstruction is valid, should not prehistoric ears 
also bear male flowers? A reexamination under the microscope shows 
that at least some of them once did and that these have since been lost 
in handling. Some of the ancient cobs, including the one illustrated 
in plate 3, figure 3, have stumps, previously unnoticed, of a slender 
stem on which male flowers were undoubtedly borne. Thus our 
genetically reconstructed ancestral form has taught us to look for 
a characteristic in prehistoric ears which we had previously over- 
looked. It has also shown us the significance of ears bearing terminal 
male spikes which are still found in certain races of corn in the coun- 
tries of Latin America: the races Nal-Tel and Chapalote of Mexico 
(9), Pollo of Colombia (10), and Confite of Peru. Finally it may 
explain some curious ears, which had previously puzzled us, molded 
in bas relief on a prehistoric Zapotec funerary urn from Mexico. The 
urn is shown in plate 4, figure 1, and the details of one of the ears in 
plate 4, figure 2. 
In bearing both male and female flowers these ears of pod-popcorn 
also resemble the lateral inflorescences of Tripsacum, a perennial grass 
and a wild relative of corn (pl. 3, fig. 3). This resemblance has in 
turn called attention to additional characteristics in which the recon- 
structed corn resembles 7'ripsacum: (1) the flowering of the female 
spikelets before the male in both lateral and terminal inflorescences}; 
(2) the many-stalked condition; (3) the small, hard, pointed seeds. 
Actually this reconstructed corn might easily be classified as an an- 
nual form of 7’ripsacum, or conversely, since corn was the first of the 
two to be given a Latin name, 7’ripsacwm could be classified as a 
perennial form of the genus Zea, to which corn belongs and which, 
until recently, has been represented by the single species Zea mays. 
These unexpected results of combining popcorn and pod corn—the 
production of a counterpart of corn’s wild relative, 7ripsacum—we 
regard as additional evidence that our reconstruction has validity. 
EVOLUTION UNDER DOMESTICATION 
Figure 4 illustrates some of the principal environmentally induced 
and genetically controlled changes which are believed to have 
occurred during domestication. The first three plants illustrate the 
genetically reconstructed ancestral form as it would be expected to 
