chises. The glumes are slightly indurated. These cobs 
appear to be related to a race, Dzit-Bacal, described by 
Wellhausen et al, which now occurs most commonly in 
Yucatan and Campeche, where it hybridizes freely with 
Nal-Tel. 
Breve de Padilla; The remaining three cobs, all large, 
cannot be definitely assigned to any race described by 
Wellhausen et al. They seem, however, to be related to 
a modern race, recently found in Mexico, in the state of 
Tamaulipas, known as Breve de Padilla (Wellhausen, 
unpublished). Since the sample comprises only three 
cobs, this identification cannot be considered as final. 
Relation of Cob Types to Archaeological Zones 
The above classification, which is based upon both ex- 
ternal and internal characteristics of the cobs, was made 
without any knowledge of the relative age of the speci- 
mens. When the cobs are also classified with respect to 
the archaeological zone in which they occurred, it is appar- 
ent that there is a correlation between type and zone 
(Table I). Cobs of Breve de Padilla and Dzit-Bacal oc- 
curred only in zone A, cobs resembling modern Nal-Tel 
only in zones A and AB (the latter probably a mixture 
of zones rather than a distinct entity). Cobs of both types 
of Early Nal-'Tel were found in both zones and were the 
only type occurring in zone B. 
There seems to be little doubt that agriculture in this 
locality began with an early type of Nal-Tel and that the 
occupation of the cave ended shortly after the introduc- 
tion of Dzit-Bacal from the south. Whether the Late 
Nal-Tel found in zone A was also introduced from the 
south or is the product of the local hybridization of Early 
Nal-Tel and Dzit-Bacal, it is not possible to determine. 
It does seem reasonably certain, however, that there was 
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