examination of the maize specimens of this second ex- 
pedition showed that the earliest cobs were even more 
primitive in some respects than those found in the 1948 
excavation and the specimens tended to confirm in gen- 
eral the principal conclusions drawn from the detailed 
study which had been made of the 1948 collection. It 
was our intention at that time to make a similar detailed 
study of the 1950 collection and to publish the results at 
an early date. In the meantime, however, the senior 
author participated in a project involving the classifica- 
tion and description of the living races of maize of Mexico 
(Wellhausen et al., 1952) and this made it possible to 
identify precursors of several living races of maize found 
in archaeological excavations in northeastern Mexico by 
MacNeish (Mangelsdorf et al., 1956) and in northwestern 
Mexico by Lister (Mangelsdorfand Lister, 1956). Studies 
of still other collections of archaeological maize had shown 
strikingly the importance of teosinte introgression in the 
evolution of maize (Galinat et al., 1956). In view of 
these developments, it was decided to postpone the final 
studies of the 1950 collection of Bat Cave specimens until 
still other collections which had come to the Botanical 
Museum from various sources could be analyzed. These 
several studies of specimens from sites in Mexico and the 
United States have been completed (Galinat and Ruppe, 
1961; Galinat and Gunnerson, 1963; Mangelsdorf et a., 
1964; Mangelsdorf et a/., in press). We can now re- 
examine the two Bat Cave collections with the benefit 
of a familiarity with the living races of maize, a con- 
siderably greater experience in analyzing archaeological 
material, and in the light of significant evidence revealed 
by other collections of which one of the most important 
is from sites in the Valley of Tehuacin in Mexico in 
which remains of prehistoric wild corn were found. 
[2] 
