328 WEATHERWAX: THE EVOLUTION OF MAIZE 
ated by male spikes (Fic. 10), ears with small female or mixed 
branches attached (Fic. 9), and perfect ears replacing the central 
spikes of sucker tassels (F1G. 12) all give indication of this. More- 
over, the early development of the two organs is the same except 
that in the case of the normal ear no side branches are developed. 
But the idea that either or both of these organs is fasciated is 
inconsistent with some important morphological facts. Carefully 
prepared microtome sections fail to show any evidence of fascia- 
tion, the development in either case being essentially the same as 
that of any ordinary floral or vegetative shoot. The only kind of 
organ of which we have any knowledge, the like of which could 
have united to form an ear, is the lateral branch of the tassel, and 
this involves a mathematical difficulty. The rows of grains on an 
ear are paired because the spikelets are borne in pairs. Ifa lateral 
spike of the tassel should contribute to the formation of an ear 
anything in terms of paired spikelets, it would be responsible for 
four rows, and this would make impossible an ear of ten, fourteen, 
or eighteen rows; but the fact remains that such ears are common. 
Harshberger’s idea that each pair of rows of grains corresponds 
to a spike of Euchlaena or Tripsacum is of no avail in getting around 
this difficulty; they bear two rows of functional spikelets, but not 
at all because of the presence of paired spikelets, for one spikelet 
of each pair is rudimentary. It may be noted, too, that although 
Worsdell has the ear formed by the union of spikes bearing two 
rows of spikelets, he has it “disrupt” into a central spike bearing 
eight rows and a number of lateral spikes each bearing four rows 
(28, pl. 30, f. 13). Incidentally it may be said that the ‘‘dis- 
rupted”’ ear figured is not abnormal at all but a normal tassel of 
a sucker. 
Collins (9, p. 526) advances another theory which probably 
offers the best explanation of the origin of both of the organs in 
question. He suggests that the male inflorescence might have 
been developed from a loose panicle by the shortening of some of 
the branches until pairs of spikelets were left on a central spike 
and a few lateral branches; the ear could easily have been de- 
veloped from this by the loss of the side branches. He abandons 
this theory for want of sufficient evidence in the form of inter- 
mediate steps, but Gernert’s Branch Corn (Fics. 14-19) supplies 
the needed evidence and strengthens a very consistent theory. 
