sacum homeolog' or counterpart for chromosome 2 has 
several wild-maize-like effects on the ear. 
The Tripsacum homeolog for maize chromosome 9 pro- 
duces a staminate tipped ear, a characteristic of wild 
maize as reconstructed in Plate XLVI. These changes 
suggestive of wild maize are not associated with increases 
in glume or rachis induration, as they might be had 
they been caused by either teosinte or Manisuris germ- 
plasm. Also both of these maizoid isolates from Tripsa- 
cum as well as others bearing several genetically marked 
chromosomes from Tripsacum are usually completely 
female fertile and at least partially if not completely 
male fertile. 
In sharp contrast are the effects of the ‘‘manisuroid”’ 
isolates which have extra chromosomes not markable by 
any of the seven marker genes of W MT maize (described 
later) which, if Manisuris is one parent of Tripsacum, 
may represent the chromosomes originally from Mani- 
suris. he manisuroid isolates tiller more profusely, have 
narrower leaves, smaller spikelets, smaller kernels, in- 
creased induration of rachis and glumes, less specializa- 
tion. between the staminate and pistillate glumes and are 
partially female sterile and usually completely male 
sterile. The tendency for the staminate and pistillate 
glumes to be more alike through a reduction in the usual 
development of wings on the pistillate glumes and a re- 
duction of the usual increased elongation of the staminate 
glumes, is of significance because with the perfect 
flowered condition of Manisuris, there is no pressure for 
glumes which are specialized into two shapes, one for 
protecting kernels, the other for protecting anthers. 
6 
‘4 term sometimes spelled homoeologue, used first by Huskins (Am. 
Nat. 75: 329-344, 1941) to designate the genetically similar chromo- 
somes in the hexaploid wheat genom. 
[ 301 ] 
