ginal part of the glume. The vascular bundles are es- 
sentially normal in structure, although they are not so 
closely spaced. 
The succulent nature of immature papyrescent glumes 
often encourages the destructive activities of ear-rotting 
fungi. This suggests that a hardening of these glumes, 
such as is caused by teosinte introgression, may promote 
resistance to pathogenic fungi. 
The gene which produces this defective character has 
been previously designated as pseudopod (Pp) (Galinat 
and Mangelsdorf, 1955), but it now seems more desirable 
to change its name and symbol to papyrescent (Pn) 
(Galinat and Mangelsdorf, 1957). This change will call 
attention to its final papery character and its similarity 
to the “‘papyrascens’’ character of Sorghum, and will 
avoid confusion with the symbols for heterozygous peri- 
‘arp color (Pp) as well. Our Px gene was originally iso- 
lated from a Peruvian variety of maize (Mangelsdorf, 
1948). It is located close to the bd (branched-silkless) 
gene near the end of the long arm of chromosome-7. Its 
linkage relations will be discussed in more detail in a 
future paper. 
Tunicate glumes. The highest tunicate allele (7'w) 
from the series of multiple-alleles at the T’u-tu locus was 
chosen in order to study, in accentuated form, the effects 
of genes at this locus. Weaker alleles at the tunicate 
locus have intermediate effects on the length, shape and 
texture of the glume (Mangelsdorf, 1948). Further dis- 
cussion of tunicate glumes will refer to the phenotype 
of the strongest tunicate allele (Plate LX, fig. 2). 
The glumes of tunicate maize are like those of most 
other grasses in being long enough to enclose the grain 
and in being foliaceous. They differ therefore, in length 
and texture from the pistillate glumes characteristic of 
the American Maydeae, including normal maize, and of 
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