Races of Zea Mays: I. Their Recognition and Classification

It is now half a century since E. Lewis Sturtevant ( '85, '86, '87, '94, '99) reviewed the variability of Zea Mays and catalogued it in six main groups, five of which were based upon the composition of the kernel.There are now available two new kinds of facts in addition to those which were at his disposal.In the first place, archeological research has made great advances and the museums of this country have numerous collections of prehistoric corn, the best of them in a remarkable state of preservation, their age approximately dated by dendrochronology (Guernsey and Kidder, '21).In the second place, the rise and development of corn genetics have provided us with a large body of technical information concerning the relationships of different kinds of corn.We know, for instance, that the change from flint corn to flour corn is controlled by a single gene difference, whereas the change from a flint to a dent is the result of many genes, so that in working out the relationships of corn the difference between flint and flour is trivial compared to the difference between flint and dent.