338 WEATHERWAX: THE EVOLUTION OF MAIZE 
reversions to the primitive two-flowered condition. We should 
not expect any one plant to show reversion in all respects; char- 
acteristics probably behave as units in reversion as much as in 
heredity. 
Some freaks, such as ears divided at the tip (17, p. 81; 14, p. 
37) and fasciated kernels (27), are probably best interpreted as 
anomalies of ontogeny, giving no more clue to the past than is 
afforded by Siamese twins or lilies with two-parted flowers. 
Indeed, an ancestral form that would be consistent with all the 
teratological ears that have been used as evidence would be an 
impossibility. It is a fact worth mentioning, also, that many of 
the teratological conditions that do not fit into the foregoing 
theory as reversions are not inherited, while those in accord with 
this theory often form the starting points of new varieties tending 
to breed true. 
It is not deemed advisable here to attempt to trace the prob- 
able origin of all the more or less fixed varieties of corn that have 
come into existence after the generic characteristics ‘were reached; 
but no constant characteristic is known in any variety, which is 
inconsistent with the general theory here outlined. The develop- 
ment of the annual habit was similar to that of teosinte, and no 
further explanation is offered. The restricted period of flowering 
has a morphological cause in the reduced number of inflorescences. 
CONCLUSION 
It is granted that the foregoing theory involves a measure of 
speculation, but that is to be expected of any theory; it is as con- 
servative as any that have been advanced to explain the origin 
of maize, and much more so than some of them. It is believed 
to be a logical deduction from the best and most recent evidences 
available, and in it are embodied parts of some of its predecessors. 
No point in it is known to be out of harmony with a rational 
interpretation of any established fact of structure, history, or 
genetic behavior concerning the plants with which it deals. 
How much of this evolution of maize was due to natural 
agencies, and how much to the influence of primitive agriculture, 
we have no means of knowing; but, from the botanical point of 
view, the changes wrought by four hundred years of civilization 
