two categories through hybridization; and ‘* Modern 
Incipient,’’ less stable races, apparently of relatively re- 
cent origin and dispersal. With the basis given by these 
authors, it should eventually be possible to make an ex- 
tensive study of archaeological remains of maize from 
Mexico and adjacent areas and to correlate in time and 
space these races with their phylogeny and with other 
culture traits. Indeed, a better framework for American 
prehistory could scarcely be desired. 
The exact origin of maize is yet unknown and will 
probably continue to be a source of speculation and con- 
troversy for some time to come. At present, the evi- 
dence seems to favor the Mexican-Central American area 
as the home of this cereal. The Chiapas-Guatemala area 
may have been the center of origin for races affected by 
introgression from teosinte (127). The Andean area has 
also been a center of dispersal, especially, it would seem, 
for large-kerneled races, including flour and sweet forms. 
(6*, 11, 16, 27, 88, 65, 66, 67, 76, 98, 94, 128, 124, 125%, 
127*, 128, 129*, 180, 181, 157, 160, 195, 211, 212*, 213%, 
218) 
THE GEOGRAPHIC ORIGINS 
oF MEXICAN CULTIVATED PLANTS 
On the basis of the data which have been discussed, it 
is possible to arrange the cultivated plants tentatively 
according to geographic origins. The divisions which are 
recognized within the Mexican-Central American region 
do not represent well defined centers or culture com- 
plexes, but rather geographic regions with some ecologi- 
cal character. Some plants probably overlap two of these 
subdivisions in their origins and a few are doubtless as- 
signed to the wrong subdivision. The divisions and assign- 
ments are, of course, distinctly tentative and subject to 
revision. 
[ 152 ] 
