GENETICS: F. M. SURFACE 481 
TABLE 1 
Characters Correlated with the Three Types of Bases on the Lower Grain 
CULTIVATED BASE 
INTERMEDIATE BASE 
WILD BASE 
Cultivated base on the upper 
grain 
Absence or abnost complete 
absence of awns on the 
lower grain 
Total absence of awns on the 
upper grain 
Absence of pubescence on the 
pedicel on the lower grain. 
Absence of pubescence on the 
pedicel on the upper grain 
None or sometimes very 
slight pubescence at the 
sides of the base of the 
lower grain 
No pubescence on the base of 
the upper grain 
Cultivated base on the upper 
grain 
Medium awns on the lower 
grain of some spikelets 
Total absence of awns on the 
upper grain 
Absence of pubescence on the 
pedicel on the lower grain 
Absence of pubescence on the 
pedicel on the upper grain 
Medium heavy tuft of hair 
at the side of the base of the 
lower grain 
No pubescence on the base of 
the upper grain 
Wild base on the upper grain. 
Very heavy awns on the lower 
grain of every spikelet. 
Very heavy awn on the upper 
grain of every spikelet 
Heavy pubescence on the pedi- 
cel on the lower grains. 
Heavy pubescence on the 
pedicel on the upper grain 
Heavy pubescence on all sides 
of the base of the lower 
grain 
Heavy pubescence on all 
sides of the base of the 
upper grain 
This and other facts have led the writer to beheve that some of these 
characters at least are controlled by separate genes. 
Characters Showing Partial Linkage. — Two characters have been dis- 
covered in this cross which apparently show partial linkage with other 
genes. These characters are (1) pubescence on the back of the lower 
grain and (2) pubescence on the back of the upper grain. These two 
characters are inherited independently of each other but the phenotypic 
appearance of the latter character is dependent upon the presence of 
the former gene in the same zygote. 
In the F2 generation the plants which have pubescence on the back 
of the lower grain segregate from those lacking this character in a 3 to 
1 ratio. The observed numbers are 347 pubescent to 118 smooth. This 
character further segregates independently of the type of base on the 
lower grain. 
On the other hand there is a very close relation between the presence 
and absence of black color and the presence and absence of pubescence 
on the back of the lower grain. The observed numbers are shown in 
table 2. 
There is an almost absolute correlation between the presence of pubes-- 
cence on the lower grain and the black color. However, two black 
plants were found which lack this pubescence entirely. The grain 
from these two plants has been carefully examined and no evidence of 
