Piare Ill. A. Three cobs from the lowest level of 
the 1950 excavation. The diagrammatic longitudi- 
nal section illustrated in Fig. | is based on one of 
these. B. An evolutionary series of Chapalote-ty pe 
cobs, the shortest from the 48-60” level, the longest 
from the 12-24” level. C. Typical kernels with 
brown (left), red (center), and colorless pericarp. 
D. A prehistoric popped kernel from the 36-48” 
level compared with a popped kernel produced by 
exposing a prehistoric kernel from the same level 
to heat. All photos actual size. 
