PLANT Coors IN Matzr 65 
has been noted. All the possible combinations of intercrosses between 
the several types have been studied, except dilute purple x brown. In 
most cases these intercrosses have been carried to the F.2 generation, 
and in several instances to F3; and Fy. Thruout the tests, the results 
have been in close agreement with those expected from the hypothesis. 
In almost every instance all the color types expected in each generation 
of the several crosses, and no others, have appeared. Moreover, the 
numerical relations found to exist between the several color types and also 
between the several classes of behavior, have been reasonably close to 
expectation. It is true that in some instances the fit of observation 
to hypothesis has not been particularly good, but even here the observed 
deviations have been of such an order as might be expected to occur 
occasionally thru the chance errors of random sampling. 
In addition to the tests afforded by the behavior of the several Fs 
color types in later generations and in intercrosses, the relations of aleurone 
color involving the factor pair A a to the several plant colors, and the 
linkage relations of the plant-color factors Pl pl with the endosperm-color 
factors Y y and of the plant-color factors Bb with the leaf-type factors 
Lg lg, have been included in the investigation. These tests have shown 
that the several color types bear to one another the relations to be deduced 
from the hypothetical genotypes assigned them. 
The conclusion seems justified, therefore, that the three-factor hypoth- 
esis proposed as an interpretation of the F. results obtained in crosses 
of purple with green has been substantiated, in so far as it is possible 
to substantiate any hypothesis. 
CROSSES INVOLVING THE MULTIPLE ALLELOMORPHS B, B”, 6’, b 
In the preceding section of this account, six color phenotypes of maize 
have been discussed, namely, purple, sun red, dilute purple, dilute sun 
red, brown, and green. In addition to these six phenotypes, green plants 
have been shown to consist of three genotypes, which in some instances 
are slightly different phenotypically. Besides these six sharply separable 
phenotypes, there exist certain intermediate forms. The constancy 
of these types from year to year, under fairly uniform environmental 
conditions, leaves no doubt that they are genotypically as well as pheno- 
typically distinct from the types considered heretofore. 
