maize did not originate from teosinte; (8) that much of 
the variation in modern maize is the product of introgres- 
sion from teosinte which occurred as a later step in the 
evolution of maize. 
The prehistoric maize remains which permit us to draw 
these far-reaching conclusions comprise a considerable 
part of the total vegetal remains isolated from the refuse 
in Bat Cave by Mr. C. Earle Smith, Jr., the junior au- 
thor of this paper, who served as botanist to the expedi- 
tion. The vegetal remains other than maize, which are 
also of considerable ethnobotanical interest, will be de- 
scribed separately by Mr. Smith. Suffice it to say here 
that, in addition to maize, seeds of both kidney beans 
and squashes were found at all except the lowest levels 
of the Bat Cave refuse in which maize itself occurs. 
Description OF Bat Cave 
Location and Climate. Bat Cave is located in Catron 
County, New Mexico, on the edge of the Plains of San 
Augustin, the basin of an ancient lake of considerable 
size Which has been described by Powers (1989). The 
longitudinal axis of the basin which lies in a northeast 
to southwest direction is about 60 miles. The basin varies 
from six to twenty miles in width. 
There are no natural streams permanently flowing into 
the basin and the plains are dry for the better part of the 
year. ‘The arroyos and canyons carry water only during 
the rainy season in July and August, when afternoon 
showers sometimes precipitate large amounts of water 
in a short period of time. Records kept at Aragon, a 
village about 25 miles from the site, indicate an average 
annual rainfall of approximately 14 inches; the precipi- 
tation, at present, on the plains of San Augustin, is 
probably a few inches less. 
Present Vegetation. The paucity of water in the re- 
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