The third has its inner surface beset with short prickles 
while the outer bears scattered hairs and prickles. The 
last specimen bears numerous short hairs on the inner 
surface and between the veins on the outer surface. The 
veins themselves bear longer and more numerous hairs 
on the outer surface. Only parallel venation was found 
on three of the four fragments; anastomosing venation 
was apparent on the fourth. 
Cutler (1946) has pointed out that the husks of maize 
are not fundamentally different from a variety of similar 
structures found in other genera of grasses, and he com- 
pares them specifically with a kind of fasciation some- 
times occurring in the genus Trichachne in which the 
lateral inflorescence is enclosed by the leaves of the culm 
on which it is borne. The husks found in Stratum II of 
the Bat Cave remains would indicate that Cutler’s com- 
parison is valid. Furthermore, the later evolution of the 
husk covering is quite consistent with the modification 
of leaf sheaths which occur in other grasses. 
The leaf sheaths which comprise the husks obviously 
became wider during the evolution of maize and event- 
ually completely enclosed the ear. The leaf blade and 
ligule were lost. The outer and inner sheaths became 
differentiated, the latter becoming thin and papery with 
anastomosing venation and were no longer capable of 
producing striations on the kernels. These changes are 
quite in keeping with the morphological pattern in other 
genera of grasses. Arber (1934), speaking of modification 
of leaf sheaths in the grasses, makes the following state- 
ment: 
An exaggeration of the size [ width] of the leaf-sheath, and a corres- 
ponding reduction in the limb, occur as part of the normal development 
in the uppermost foliage leaf enclosing the inflorescence in many grass- 
es, such as Phalaris canariensis L. and Alopecurus pratensis L. In the 
xerophytie South African grass, Ehrharta aphylla Schrad., this type of 
change has gone so far that the lamina is reduced to a mere point.’’ 
"Reference to figures omitted in this quotation. 
[ 233 ] 
