EXPLANATION OF THE ILLUSTRATION 
Piare XXV. A comparison between archaeological 
cobs showing teosinte introgression in the Richards’ 
Caves material (A, C) and their counterparts (B, D) 
produced experimentally from maize-teosinte hy- 
brids. The modern specimens have been boiled in oil 
in order to produce the dark coloration characteristic 
of the prehistoric specimens. Note the similarity 
within pairs in regard to highly lignified crateriform 
lower glumes which diverge at right angles from a 
highly lignified rachis. Natural size. 
