As in the leaf, stomata occur along both epidermal 
surfaces. In the glume, however, they are vestigial and 
obscure along the outer epidermis. Such reduction may 
result from the extreme lignification of the underlying 
tissue. Rather well-developed stomata are found on the 
inner surface directly opposite the larger vascular bun- 
dles. The fact that the maize-glume has stomata and yet 
does not have an opportunity to function in photosyn- 
thesis, seems to emphasize the leaf-like nature of this 
organ. 
The outer epidermis has a glabrous cuticle and may 
acquire a brown, red or purple coloration from the action 
of certain genes. Epidermal pubescence is greatly re- 
duced, except in the lateral wings. 
Papyrescent glumes. This dominant mutant is charac- 
terized by glumes which upon final maturation become 
papery and similar in texture to that which occurs in lem- 
mas, paleas and lateral wings of normal glumes, as well 
as in the ligules of normal leaves (Plate LX, fig. 1). These 
papyrescent glumes are usually slightly longer than the 
mature grain. A condition which is superficially similar 
to the papyrescent character develops in normal ears 
which are poorly matured. This simulation results from 
the protrusion of the lemmas, paleas and papery wings 
from normal glumes above chaffy or small grains. 
The papyrescent character is likewise similar or iden- 
tical with the ‘‘palee sviluppate’’ of Bonvicini (1932) and 
apparently with the recessive ‘‘semivestidos’’ of Andrés 
(1950). Our character for papyrescent glumes may have 
been incorrectly identified by Andrés as a recessive fac- 
tor since the effects of this semi-dominant gene are not 
always readily apparent in the heterozygote. It has also 
been confused by Weatherwax (1954) with half-tunicate, 
from which, as will be pointed out later, it is histologi- 
cally distinct. Furthermore, we find a counterpart of the 
[ G4 | 
