54 Journal of Agricultural Research voi. xxvn, no. x 
EXPERIMENTAL MATERIAL AND METHODS 
Several crosses between different varieties of grain sorghums were 
made by the writer at the Woodward Field Station, Woodward, Okla., 
in 1919 and 1920. Some of these have been grown through the F 3 
generation, while the remainder have been carried through the F 2 genera¬ 
tion. The crosses discussed in this paper are (1) feterita X Sunrise 
kafir and its reciprocal, (2) Sunrise kafir X Blackhull kaoliang, (3) 
feterita X Red kafir, (4) Sunrise kafir X Red kafir, (5) White kafir X 
Red kafir, and (6) White kafir X Sunrise kafir. 
SEED COLOR OF PARENT VARIETIES 
Feterita kernels are chalky or starchy white in external appearance, 
but portions of the seeds frequently are stained a dark red. This dis¬ 
coloration is most apparent on that part of the kernel covered by the 
glumes. The kernels of the selection of Blackhull kaoliang used in this 
study have the same sublenticular shape and peculiar chalky white 
color as those of feterita. It was selected from the progeny of bulk seed 
of Barchet kaoliang obtained in 1915 at the Amarillo Cereal Field Station. 
From the shape and color of the seeds, it is believed to have arisen through 
natural crossing between this kaoliang and feterita. 
Sunrise kafir has the typical seed color of the white-seeded kafirs, 
creamy white with a more glossy surface than that of feterita and the 
Blackhull kaoliang hybrid. White kernels of kafir usually are marked 
with reddish black spots which occur most often at the point of attach¬ 
ment of the style. These spots vary in size and seem to be influenced 
to some extent by the environmental conditions that obtain during 
kernel development. 
Red kafir kernels are dark brownish orange or brownish red with a 
smooth or glossy appearance. Frequently the color is not uniform over 
the kernel, due to bleaching where exposed to the weather. 
Kernels of feterita and Blackhull kaoliang possess a layer of compara¬ 
tively thick brown cells directly outside of the aleurone layer. This 
layer of cells is designated as the nucellar or hyalin layer, by Winton ( 10 ), 
the seed coat (Samenschale) by Harz (5, p. 1249-1254), and hyalin layer 
(Hyalinschicte) by Mitlacher (7), and probably is analogous to the inner 
integument in Johnson grass as described by Harrington and Crocker (3). 
Whatever this layer occurring directly outside of the aleurone layer may 
be called, it consists of relatively large cells containing a dark brown 
pigment. In Sunrise and other white kafirs, and in Red kafir, this layer 
of dark brown cells is absent. Winton (10) made a microscopic exami¬ 
nation of the seeds of 11 varieties of sorghum. Of these, a nucellar layer 
was found in three varieties of broomcom, Early Amber and Early 
Orange sorgos and Brown durra. The other varieties, White and Red 
kafir, White and Yellow milo, and White durra, had no nucellar layer. 
Winton's studies and the writer's examination of kernels of many sor¬ 
ghum varieties indicate that brown seed color is an indication of a brown 
nucellar layer. Feterita, Blackhull kaoliang, and Dwarf hegari have 
white seeds with a brown nucellar layer. A casual examination shows 
that these three white-seeded varieties which have a nucellar layer are 
chalky or starchy white in color, differing in this respect from many 
other white-seeded sorghums. 
