Reconstructing the Ancestor of Corn’ 
By Pau C. MANGELDORF 
Professor of Botany 
Harvard University 
[With 4 plates] 
Our PurpOsE in reconstructing the ancestor of corn is to retrace, as 
far as possible, some of the principal steps which have been involved 
in its evolution under domestication. We do this in the hope of gain- 
ing a better understanding of the corn plant as one of those unique 
biological systems which man employs on a grand scale to convert 
the energy of the sun, the carbon dioxide of the air, and the minerals 
of the soil into food. Corn is one of perhaps not more than a dozen 
species of cultivated plants of worldwide importance—each one the 
principal source of food of millions of people—which quite literally 
stand between mankind and starvation. 
But corn is something more than an important food plant; it is 
also a mystery, a fascinating botanical mystery, as challenging to a 
scientist as is a mountain to an exployer. 
A UNIQUE CEREAL 
Modern corn, our starting point in this study,” is unique among the 
cereal grasses in the nature of its inflorescences [1, 2]. The terminal 
inflorescence, commonly called the “tassel” (fig. 1, A, C), usually 
bears only male flowers, each of which contains three pollen sacs or 
anthers (fig. 1, D) packed tightly with some 2,500 pollen grains. 
These are small, about 1459 inch in diameter, light in weight, and 
are easily carried by the wind. 
The lateral inflorescences (fig. 1,4, 8), which when mature become 
the familiar ears of corn, have only female flowers which bear the 
1 Paper presented at the annual meeting of the American Philosophical Society, Apr. 25, 
1958. Reprinted by permission of the Society from the Proceedings, vol. 102, No. 5, October 
1958. 
?The research reported in this article was supported in part by a grant from the Na- 
tional Science Foundation. I am indebted also to Dr. Walton C. Galinat for his assistance 
in some aspects of these studies as well as for the drawings reproduced in figures 2, 3, 
and 4. 
8 Numbers in brackets indicate references at the end of text. 
495 
