176 PAUL C. MANGELSDORF 



INTERRACIAL HYBRIDIZATION IN MAIZE 



For additional evidence on interracial hybridization in maize we may 

 turn to existing races of maize. Among these the Mexican races are of par- 

 ticular interest and significance, not because maize necessarily originated in 

 Mexico, since there is considerable evidence that it did not, but because 

 Mexico is a country where primitive races, which in other places are to be 

 found primarily as archaeological remains, still exist as living entities. It 

 is possible in Mexico to find all stages between ancient primitive races and 

 modern highly-developed agricultural races. One has only to place these 

 racial entities in their proper sequence in order to have at least the outline 

 of an evolutionary history. 



Wellhausen et al. (1951) have recently made a comprehensive study of the 

 races of maize of Mexico. They recognize twenty-five distinct races as well 

 as several additional entities which are still somewhat poorly defined, but 

 some of which may later be described as races. They divide the known races 

 into four major groups as follows: 



Group No. Races 



1. Ancient Indigenous 4 



2. Pre-Columbian Exotic 4 



3. Prehistoric Mestizos 13 



4. Modern Incipient 4 



Origin of Mexican Races of Maize 



Ancient Indigenous races are those which are believed to have arisen in 

 Mexico from the primitive pod-pop corn similar to that whose remains were 

 found in Bat Cave in New Mexico. The races in this group are called in- 

 digenous not because they necessarily had their primary origin in Mexico, 

 but because they are thought to be the product of indigenous differentiation 

 from a remote common ancestor. The differentiation is assumed to have re- 

 sulted from independent development in different localities and environ- 

 ments with hybridization playing little if any part. 



Four races of the Ancient Indigenous group — Palomero Toluqueno, Arro- 

 cillo Amarillo, Chapalote, and Nal-tel — are recognized. All of these, like their 

 primitive ancestor, are pop corn. Two of the four — Chapalote and Nal-tel — 

 are forms of pod corn. All have small ears, and all are relatively early in 

 maturity. 



Pre-Columbian Exotic races are those which are believed to have been 

 introduced into Mexico from Central or South America before 1492. Four of 

 these races — Cacahuazintle, Harinoso de Ocho, Oloton, and Maiz Dulce — 

 are recognized. The evidence for their antiquity and exoticism derives prin- 

 cipally from two sources: all have South American counterparts; all except 

 Maiz Dulce have been parents of hybrid races, some of which are them- 

 selves relatively ancient. 



