the main flow of genes appears to be from teosinte 
to maize, since the genetic incorporation of a maize- 
like rachis results in the inability to disperse seed and 
the extinction of these maize introgressed teosinte 
plants. 
It is postulated that the hybridization of teosinte and 
maize on the Central Plateau in the past is compara- 
ble to the present hybridization of teosinte and maize 
at Nobogame. This hypothesis accounts for both the 
widespread presence of tripsacoid characteristics in 
the maize of the Central Plateau and the maizoid 
characteristics of the teosinte. The introgression of 
teosinte segments following maize X teosinte hybrid- 
ization would have been of positive selection value if 
it resulted in a larger ear. 
{ 310 | 
