EXPLANATION OF THE ILLUSTRATION 
Prare Il 
A. Tripsacum dactyloides 2n (Kansas clone) 
B. Maize (Nal Tel) 
C. ‘Teosinte (San Antonio Huixta) 
LD. Maize-Tripsacum hybrid (WMT maize “ T'ripsacum dactyloides) 
Explanation 
ry : ee . ss . 
A. These two photographs show a typical wild’’ exine pattern, as 
described by Rowley. The spinules appear clumped and are often 
visually merged together. In the small photograph, a faintly incised 
reticulum can be discerned (seen as a greyish network). 
B. Typical pure maize pattern. The spinules are evenly distributed. 
There are only two levels of phase retardation — the spinules them- 
selves (dark) and the ektexine surface (light). 
C. Typical primitive teosinte pattern. In the small photograph, the 
spinules appear clumped, with patches of light and dark areas visible. 
The large photograph shows the spinules to be rather evenly distrib- 
uted, but adjacent spinules often appear connected, so that it is difh- 
cult to isolate individuals. 
D. In this hybrid, some features of both maize and 7'ripsacum are 
apparent. The spinules are unevenly distributed and clumped, leav- 
ing lacunae larger than those associated with either maize or teosinte, 
but less pronounced than those of Tripsacum. 
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