In spite of the great amount of archaeological salvage 
work done in the Missouri River Basin since about 1946, 
the dating of the beginnings of sedentary farming cul- 
tures in the Dakotas is not exactly known, but Wedel 
(1961) considers it later than the beginning of Upper 
Republican farther south. In central South Dakota, 
Lehmer (1954) and others recognize a blending of two 
traditions: one from the East and one from the Central 
Plains, of which Upper Republican is a classic example. 
The fact that this blending took place apparently well 
after the beginning of the Central Plains tradition helps 
support a southern or southwestern origin of maize in 
the Plains. 
Later sites in the Plains, most of them dating from 
after ca. A.D. 1600, have yielded specimens of maize 
with a very significant percentage of eight-rowed cobs 
that are predominantly Maiz de Ocho. At some sites, 
the maize is entirely eight-rowed. Farther east, across 
the northern United States, Brown and Anderson (1947) 
showed the same pattern, with a general tendency for 
the percentage of eight-rowed specimens to be higher in 
the extreme north. Furthermore, all the sites across the 
northern United States from which specimens of maize 
have been collected are apparently of a date later than 
ca. A.D. 1000 (Brown and Anderson, 1947). As the 
area of maize cultivation expanded north, natural selec- 
tion would have played a very important part in filtering 
out Maiz de Ocho germplasm in the form of the North- 
ern Flint, which was the sole historic Indian maize from 
the Dakotas across the northern United States to the 
Atlantic Ocean. 
In any case, the introduction of Maiz de Ocho into 
what is now the United States probably did more to 
change the way of life of more of its people in a short 
time than did any other single prehistoric innovation. 
[ 186 ] 
