New EviIpENCE ON THE NATURE OF THE Maize Ear 
Evidence for Fusion 
The fusion hypothesis, as has already been mentioned, 
has been, to a large extent, dismissed because (a) ana- 
tomical and other evidence for fusion has been lacking 
and (b) it has been thought that the hypothesis leads to 
mathematical inconsistencies with regard to row number. 
New evidence renders both of these objections somewhat 
less pertinent than they previously were. 
During the summer of 1944, Mrs. P. C. Mangelsdorf 
in taking notes on the number of ranks in the central 
spike of tassels among segregates of maize-teosinte hy- 
brids, encountered a clear-cut case of fusion of two of the 
lateral branches of the tassel. This is illustrated in Fig. 
1. The two branches are joined for a distance of slightly 
more than half of their length. There is no doubt that 
this is a case of fusion rather than fasciation for the lower 
region in which the two parts are joined is distinctly four- 
ranked, a condition which I have never before encount- 
ered in a lateral branch of the tassel, while the two un- 
joined parts of the upper region are both distinctly 
two-ranked and differ in no important detail from the 
remaining branches on this tassel. 
The fused portion of this branch is not radially sym- 
metrical but exhibits a distinct dorsiventral, character 
since only the adjoining edges of the two component 
parts are fused. Had the two entire dorsal surfaces of the 
branches become fused, or had a third branch become 
fused at both of its edges to the free edges of the other 
two, thus forming a cylinder, the structure would have 
been indistinguishable from the central spike of the tassel. 
This single specimen makes it clear that a polystichous 
structure similar to the central spike of the tassel (which 
is the homologue of the ear) can arise in maize through 
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