56 
Journal of Agricultural Research 
Vol. XXVII, No. x 
to seed color—(i) brown or light brown, with a brown nucellar layer; (2) 
chalky or starchy white, with a brown nucellar layer, similar to the 
feterita parent; and (3) creamy white with no brown nucellar layer, similar 
to the Sunrise kafir parent. To determine the presence or absence of the 
brown nucellar layer, a kernel was taken from each head and the outer 
coat scraped off with a knife. This method of determination proved 
to be accurate and satisfactory. 
Some of the crossed seeds obtained in 1919 were not sown until 1921, 
when several Fj heads were selfed. One head row of F 2 plants of Sun¬ 
rise kafir X feterita and three head rows of the reciprocal cross were 
grown in 1922. This F 2 material was similar to that obtained in the 
preceding year. Data on the distribution of seed color in the F 2 of this 
cross and its reciprocal are shown in Table I. 
Using the method of Harris (4) for testing the goodness of fit of Men- 
delian ratios, x 3= 3-86 and />= .1476, or a variation of the size obtained 
might be expected once in seven cases, due to random sampling. It 
appears that the segregation of color factors in a Sunrise kafir X feterita 
cross was according to the dihybrid ratio of 9: 3: 4. To explain this in¬ 
heritance the following factors may be assumed : 
By a factor for brown nucellar layer which also may cause brown in the 
epidermis if 5 is present. Its allelomorph b , gives kernels without a 
brown nucellar layer. 
S, a factor for smooth or glossy pericarp. When 5 is present the peri¬ 
carp is glossy and may be creamy white, as in white kafir, or may 
carry other colors. Its allelomorph s f gives a chalky white pericarp. 
Brown does not appear in the pericarp of an ss plant. 
The parents and F x hybrids, so far as shown by the results of this 
cross, then would have the following factorial composition: 
Feterita. BBss. 
Kafir. bbSS . 
Fi hybrid. BbSs. 
The F t kernels having one B factor have a brown nucellar layer. As 
an 5 factor also is present, the brown color appears in the epidermis. 
The F 2 results seem to substantiate this hypothesis. The results expected 
in the F 2 generation, from an independent recombination of the two 
factors just designated, would produce three phenotypes classified as 
follows : 
Brown seeded, with 
brown nucellar layer. 
Chalky white seeded, 
with brown nucellar 
layer. 
Glossy white seeded, 
with no brown nucellar 
layer. 
I BBSS 
1 BBss 
i bbSS 
2 BBSs 
2 Bbss 
2 bbSs 
| 2 BbSS 
— 
1 bbss 
j 4 BbSs 
3 
— 
1 9 
4 
The data presented in Table I are in substantial agreement with the 
hypothesis here presented. The bbss seeds with a chalky white color, 
but with no brown nucellar layer, because of weather effects, are difficult 
to distinguish when this chalky white is not over a brown nucellar layer, 
