278 WEATHERWAX: THE ANCESTRY OF MAIZE 
On the other hand, comparative morphology, which has been 
one of the most reliable and productive agents in establishing 
lasting theories of evolution, points out clear-cut, logical, reason- 
able evidence of the direct origin of Zea, codrdinately with Eu- 
chlaena and Tripsacum, from an ancestor long ago extinct. There 
has been pointed out no accepted fact whose rational interpreta- 
tion discloses any inconsistency in the theory. The three genera 
are different simply because they have lost different organs that 
were possessed by their progenitor and have specialized others to 
different degrees. 
INDIANA UNIVERSITY, 
BLOOMINGTON, INDIANA 
LITERATURE CITED 
1. Kempton, J. H. The ancestry of maize. Jour. Wash. Acad. Sci. 
Oi 3-81 Toss. 
2. Collins, G. N. The origin of maize. Jour. Wash. Acad. Sci. 2: 
520-530. 1912. 
