little change in Early Nal-Tel itself during the period 
represented by these remains. There is no significant 
change from zone to zone, either in the frequency of 
types A and B of Early Nal-Tel or in their characteris- 
tics. Certainly there is no evidence that this race was im- 
proved by selection, either natural or artificial, during 
Specimens Zone 
Cobs, Race or Type A AB High B Low B _ Totals 
Breve de Padilla 3 3 
Dzit-Bacal 6 6 
Late Nal-Tel 14 4 18 
Early Nal-Tel Type B 17 6 2 11 36 
Early Nal-Tel Type A 19 3 1 1 24 
Total cobs 59 13 3 12 87 
Fragments of cobs 24 5 2 31 
Husks 22 31 3 56 
Quids 2 1 3 
Total maize specimens 107 49 8 13 177 
* There are, in addition, three cobs loaned to the Museum of An- 
thropology, University of Michigan, which were not analyzed. 
this period. Improvement did not come about until 
something new was introduced, from the south, or hy- 
bridization occurred in the area. 
Late Nal-Tel, which first appears in zone AB, but 
which, since zone AB probably represents a mixture, 
may actually be confined to zone A, is definitely a dif- 
ferent type of maize than Early Nal-Tel, as the data in 
Tables II and III show. 
One of the important differences between these two 
types is in teosinte introgression. This almost invariably 
affects the texture of the lower glumes, causing them to 
become lignified and indurated. In Early Nal-Tel, of 
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