of the Sierra Madre mountains. This rises to a height of 
3,000 feet and is covered by a tropical rain forest with 
large pines on the summits. Further to the west, the 
valleys gradually become narrower and more canyon- 
like, with a more xerophytic vegetation in which maguey, 
cactus, mesquite and chaparral predominate. The moun- 
tains are higher (over 5,000 feet) with a thin cover of 
pines on their rocky summits. In this region we were 
fortunate enough to find three dry caves with stratified 
deposits representing eight cultures, associated in the 
main with abundant, preserved food remains (including 
beans). 
We must first describe the archaeological findings in 
order to present an adequate background for an analysis 
of the bean remains. ‘The sequence is based upon strati- 
graphy from three caves which is in part confirmed by 
Carbon 14 dates (see Table 1). Study of the artifacts 
from the various occupation levels in the caves revealed 
similar sequential cultural complexes. Romero’s Cave 
(Tm ¢ 247) had sixteen occupation levels and a few art- 
ifacts below them belonging to the Infiernillo, Ocampo, 
Guerra, Mesa de Guaje, Palmillas, San Lorenzo and San 
Antonio complexes. Valenzuela’s Cave (Tm c 248) con- 
tained nine stratified layers belonging to the Infiernillo, 
Ocampo, Flacco, San Lorenzo and San Antonio com- 
plexes, all of which had associated vegetal materials. Ojo 
de Agua Cave (Tm c 274) had twelve occupations and 
cultural remains representing the Infiernillo, Flacco, 
Palmillas and San Lorenzo complexes. Only the upper 
Palmillas level had preserved food materials. ‘The accom- 
panying chart Table I illustrates the dating and correla- 
tion of the stratigraphy of the three caves. 
THE SEQUENCE OF CULTURAL PHASES 
In briefly summarizing the cultural complexes, we 
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