Pirate XXVII. A fragment of husk found in Stra- 
tum II and the kind of ear which it must once have 
covered, about two thirds natural size. The husk 
consists of four leaf sheaths which show no evi- 
dence of ever having enclosed an ear. They proba- 
bly formed an involucre around the base of the ear. 
Pirate XXVIII. Diagrams illustrating the cross 
sections of cobs of Bat Cave maize and ears of mod- 
ern varieties. Upper Row. Four cobs from Bat 
Cave showing a progressive increase in the size of 
the rachis accompanied by a progressive increase 
in the row number and a decrease in the glume 
zone. Second Row. Diagrams of three degrees of 
half-tunicate in an isogenic stock showing how the 
lower alleles increase the diameter of the rachis, 
reduce the glume zone and shorten the distance 
between the rachis and the base of the kernels. 
Third Row. Diagrams of two degrees of tunicate 
in an isogenic stock illustrating the same phenom- 
ena described above. Fourth Row. Three ears of 
modern maize illustrating various stages in the 
evolutionary trend toward a massive rachis, short 
glumes and compact rachillae. 
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