380 
Journal oj Agricultural Research 
Vol. XXX, No. 4 
other red oat varieties, was very evident 
in the Fi plants. The lemmas were 
reddish-yellow like those of Fulghum, 
but in shape they were rather plump 
like those of Swedish Select. One 
plant was practically awnless, while 
about 25 per cent of the spikelets on 
the other were awned. The awns were 
somewhat twisted and dark at the base 
like those of the Swedish Select parent, 
but only slightly bent. It is thus seen 
that in respect to the presence of awns 
this cross behaved similarly in the Fi 
to the Sixty-Day X Burt cross, reported 
by Fraser (5 ). 
SECOND GENERATION PROGENY 
Altogether, 118 F 2 plants were grown 
from the seed of the two Fi plants at 
the Aberdeen Substation, Aberdeen, 
Idaho, in 1918. Samples of these 
plants have been preserved and an 
attempt has been made to classify 
them with regard to the degree or 
extent of awning, disjunction of the 
second floret, and color of lemma, 
primarily to determine if any rela¬ 
tionship exists between these char¬ 
acters and smut resistance. It is fully 
realized that the number of F 2 plants 
is entirely too small for the determina¬ 
tion. of genetic ratios. Further, an ex¬ 
tended discussion on the inheritance 
of these characters is not within the 
province of this paper. 
Of the 118 plants, 25 were classed as 
having few or no awns (awnless), 76 
as having abundant awns (fully awned), 
and the remaining 17 as being inter¬ 
mediate or commonly awned (approxi¬ 
mately 50 per cent of the spikelets 
awned). These numbers do not even 
indicate the ratio of 1 awnless, 2 partly 
awned, and 1 fully awned, obtained by 
Fraser ( 5 ) from a cross between an 
awnless strain of Sixty-Day and Burt, 
the latter an exceedingly variable 
variety with regard to awns and other 
kernel characters. Provided the mode 
of inheritance is the same in this cross, 
the small F 3 population may account for 
this wide deviation from the expected 
ratio. However, the preponderance of 
awns in the F 2 plants probably is best 
explained by the fact that Swedish 
Select usually is a rather fully awned 
variety, and that frequently in Ful¬ 
ghum as many as 50 per cent of the 
spikelets are awned. As a conse- 
sequence, it could not be expected 
that the genetic behavior regarding 
awns would be the same as in a cross 
where one parent is awnless and the 
other only partly awned. 
Of the 76 plants with abundant 
awns, about 16 showed the twisted and 
geniculate awn frequently occurring in 
the Swedish Select parent, which type 
of awn apparently occurs less fre¬ 
quently than the nontwisted straight 
awn of the Fulghum parent. 
Classification with regard to the dis¬ 
junction of the second floret or lemma 
of the spikelet (separation of second 
floret from the first) was most difficult. 
Those plants in which the second floret 
was attached rather firmly to the first, 
and on separation usually carried its 
rachilla segment with it, were classed 
as attached (sterilis of Fraser), while 
those in which the second floret dis¬ 
articulated easily, the rachilla seg¬ 
ment usually remaining on the first 
floret, were classed as disarticulated 
(sativa of Fraser). The remaining 
plants in which no differentiation was 
possible were classed as intermediate. 
On this basis, therefore, 25 were 
classed as attached, or as having the 
disjunction of the Fulghum, and 13 as 
disarticulated, or as having the dis¬ 
articulation of Swedish Select, and 80 
as intermediate between the two. 
Fraser (5), in his observations on the 
cross Sixty-Day X Burt, obtained a 
ratio of 1 sterilis, 2 intermediate, and 1 
sativa. The numbers obtained in the 
present cross indicate this ratio, but 
do not approach it very closely. 
On the basis of color of lemma, 
classification was even more difficult 
than in the case of awning and dis¬ 
junction. Because of the blending of 
one color into the other in the same 
plant no very satisfactory classifica¬ 
tion could be made. The color of the 
lemmas varied from reddish-yellow to 
yellowish-white. There were really 
three colors present which have been 
described as reddish-yellow, yellow, 
and yellowish-white. However, dif¬ 
ferentiation between reddish-yellow and 
yellow, as well as between yellow and 
yellowish-white, was most difficult in 
some plants. Of the 118 plants about 
32 were classed as not definitely falling 
into the reddish-yellow or yellow class. 
Of the remaining 86, there were 28 
of a reddish-yellow typical of the color 
in Fulghum, and 58 lighter in color, 
and in most cases a true yellow. The 
dominance of the reddish-yellow color 
of the Fulghum over the white of 
Swedish Select in the F 2 generation of 
the cross in question, is indicated. 
While this classification on the basis 
of certain kernel characters is not all 
that could be desired, it is believed 
worth while, however, in that it will 
indicate in some measure whether there 
is any relationship between morpho¬ 
logical characters and smut resistance 
or smut susceptibility (pi. 3). 
The spikelet descriptions of the 92 
F 2 plants used in the smut-inoculation 
experiments reported herein are shown 
