Changes in Pericarp Color 
The majority of the kernels are so well preserved that 
it is possible to classify them with respect to pericarp 
color. Of the 2938 kernels so classified: 116 are brown, 
38 red, 138 variegated, 2 with colored aleurone, and 124 
with colorless pericarp and aleurone. 
The kernels with brown pericarp are more frequent in 
the lower levels than in the higher and they are smaller 
on the average than the kernels with red or colorless 
pericarp. The fact that the kernels from the lower levels 
of Bat Cave are predominantly brown suggests that this 
is the primitive or “‘wild’”’ color. Also most of the early 
prehistoric corn in South America has brown pericarp 
color as do the kernels of corn’s relative, teosinte and 
Tripsacum. 
Pericarp color in maize is the product of the inter- 
action of genes at two, in some cases three, different loci. 
Brown pericarp results when the P factor on chromosome 
1 interacts with one of the several alleles at the A locus 
on chromosome 8: A”, a”, anda, Since the kernels 
from the lower levels are predominantly brown and since 
the a, allele is not common in maize, it seems probable 
that the genotype of the early kernels is 4" 4%PP. The 
red kernels probably represent mutations to 4, perhaps 
resulting from the introgression of teosinte which is 
known to have mutagenic effects (Mangelsdorf, 1958). 
Variegated Pericarp. Thirteen of the 299 kernels had 
variegated pericarp. This variegation is the product of 
a mutation system which has been intensively studied 
by Brink and his associates and which involves the inter- 
action of genes at the P locus on chromosome 1 with a 
genetic factor designated as ‘‘modulator’’ which may 
occupy various positions on chromosome | or on other 
chromosomes. The fact that nine of the 13 variegated 
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