A CHRONICLE OF THE TRIBE OF CORN 235 



•spikelets grown together; the same part in teosinte consists of bundles 

 of distinct two-rowed spikelets with jointed axes. It takes two steps 

 to bring maize to something like this condition. Ordinary maize va- 

 rieties often produce individuals that have ears branched in much the 

 same manner as the tassel or male spike. This is probably a reversion 

 toward a former type. At least, pure varieties of this kind can be iso- 

 lated. Furthermore it can be shown by crossing that the branched con- 

 dition is due to a single hereditary character that has been lost by the 

 cultivated kinds. The other step is the increase in number of rows, 

 giving us the fine ears with from 18 to 24 rows that take the prizes in 

 the agricultural shows. This feature is probably not due to the grow- 

 ing together of the spikelets. It is much more likely that increased 

 number of parts came about through progressive variations, much as 

 the increase of petals has brought the horticulturist so many double 

 flowers. This type of variation is very common and still continues in 

 maize, for the prize ears of the exhibitions contain many more rows 

 than the more ancient little flints that were grown by the east coast 

 red men. 



The fact that but two essential variations, kinds that continue to 

 occur, separate teosinte 2 from the maize nearest like it, combined with 

 the fact that the two are fertile in crosses lead me to believe that the 

 two plants are simply diverse types of the same polymorphic aggrega- 

 tion, although they may be called species if one desires. 



Perhaps we should stop here and not follow the path of speculation 

 to its uttermost limit; still there are two more backward steps indi- 

 cated by studying the cultivated plant. The plant is monoecious; that 

 is, the male organs and the female organs are borne in separate flowers, 

 though both are found on the same plant. This condition is not un- 

 common among the grasses although it is not the primitive condition. 

 The unique fact is that the female flowers that form the ears are borne 

 on short branches in the axils of the leaves of the maize stalk, while the 

 male flowers are borne in a terminal spike, the tassel. This method of 

 flowering is not so peculiar if the ear branch is examined. The husks 

 that surround the ear are merely the leaves of the lateral branch upon 

 which the ear is borne as a terminal spike. The lateral branch has 

 simply shortened. It is telescoped together until the distance between 

 the nodes is sometimes not more than an eighth of an inch. It seems 

 just to conclude from the number of these internodes that the ear branch 

 was at one time as long as that portion of the main stalk above the ear, 

 that the flower spikes of the ancestral plant were once more or less level 

 topped, bringing them into a horizontal plane. What caused the change 



2 There are a large number of characters of less importance separating 

 maize and teosinte that show that the two plants have developed along different 

 lines after their separation from an ancestor more like both. 



