key to the enormous diversity found in so many species 
of cultivated plants and domestic animals. Here, too, 
perhaps, is a clue to the rapidity with which organisms, 
in nature, can evolve in the face of drastic changes in 
the environment. 
EVOLUTION OF THE Husks 
Although only eight specimens of husks were found 
in the Bat Cave remains, these differ sufficiently in their 
characteristics from stratum to stratum to allow some 
far-reaching inferences to be drawn with respect to the 
nature of the primitive maize inflorescence and the evo- 
lution of husks during domestication. 
No specimens of husks were found in the lowest stra- 
tum. Only one specimen was found in Stratum IT, but 
this single specimen, although it represents the husk 
covering of less than half of the ear, has an extremely 
important story to tell. 
The husk appears to be intact with respect to length 
and reaches a maximum length of 24.5 em. Four leaf 
sheaths are included, and the number may tell some- 
thing of the relative height at which the ear arose. If 
primitive maize resembled either of the maize relatives, 
teosinte or Tripsacum, its lateral branches would have 
had a node number approximately equal to the node 
number on the primary stalk above the point of origin 
of the branch. This allows us to infer that the ear was 
borne at the fifth node below the tassel, but it tells us 
nothing about the number of nodes which might have 
occurred below the ear. 
All husks have prominent parallel veins widely spaced. 
There is no anastomosing venation. It is primitive, un- 
differentiated husks of this type which produce the “‘stri- 
ations’’ on the surface of the kernels in ears which are 
tightly enclosed in husks (Anderson 1944a). Striated ker- 
[ 281 J 
