334 WEATHERWAX: THE EVOLUTION OF MAIZE 
material, and they are never any better than the morphology upon 
which they are based. 
Ancestry of maize.—It is neither necessary nor desirable, I 
believe, to look for the ancestor of maize and its near relatives 
in any plant now living; its evolution along different lines to 
the present forms would imply its own probable disappearance. 
There are found in different members of the Andropogoneae, 
however, all the characteristics necessary for a theoretical pro- 
genitor of maize and its American relatives. In the evolution of 
these plants from their common ancestor, many steps were prob- 
ably taken, no suggestion of which has passed down to modern 
times. It is almost certain that the Asiatic species of the Maydeae 
arose from this same stock, and many lines of descent may have led 
to other forms now long extinct. Geology and archeology are of 
little value to us in solving these problems, since the oldest remains 
of these plants found in the rocks or in human habitations are 
practically modern. 
Theoretically the ancestor of these plants was an herbaceous 
Maydeae and some of the Andropogoneae as well, have been 
evolved by the suppression of parts, whose rudiments are, in most 
instances, still to be found in the modern plants. 
The cause of this suppression and the mechanism of its accom- 
plishment are unsolved problems, but the phenomenon is not 
peculiar to this group of plantsalone. It is known that monoecism 
among the angiosperms has been reached independently in many 
groups as a result of the suppression of one set of organs in each 
