strata of maize remains in nearby Tularosa Cave studied 
by Cutler (1952). At least three of the Tularosa Cave 
cobs illustrated by Cutler appear to be highly ‘‘T'ripsa- 
coid’’ (a term used first by Anderson and Erickson in 
1941 to describe maize which tends, in some of its char- 
acteristics, to resemble Tripsacum). Also, some of the 
prehistoric cobs from the Hueco Mountain Caves in 
western Texas, as illustrated by Cosgrove (1947, Fig. 
65), resemble those of Tripsacoid maize. 
Archaeological material recently excavated from two 
caves in Arizona has yielded more abundant evidence on 
the role of teosinte (or Tripsacum) in the evolution of 
modern maize. This material, collected by the junior 
author, Mr. Lloyd Pierson, comes from Richards’ Caves 
near Montezuma Castle and from the lower ruin in the 
Tonto National Monument in Arizona. It consists of the 
unusually large total of 8,342 well-preserved cobs, as 
well as numerous kernels, husks, shanks and tassel frag- 
ments. Its age is estimated at from 500 to 700 years. 
Among the cobs are specimens which resemble closely 
those which occur in the F2 and backcross generations 
of maize-teosinte hybrids. In fact, it is possible to match 
many of these archaeological specimens, feature for fea- 
ture, with modern cobs of segregates of maize-teosinte 
hybrids (Plates XXV and XXVI). These Tripsacoid 
cobs tend to be more indurated than the ‘‘pure’’ maize 
cobs in the same collection. This is regarded as highly 
significant, for one of the conspicuous differences between 
maize and its two relatives, teosinte and Tripsacum, is 
in the induration of the tissues, especially those of the 
rachis, cupule’ and lower glumes. In both teosinte and 
Tripsacum, the caryopsis is enclosed in a hard, bony case 
'The cupule or alveolus is a lignified structure thought to represent 
a prophyll adnate to the rachis, and to be borne on a reduced primary 
branch which bears a pair of pistillate spikelets (Nickerson, 1954). 
{ 102 | 
