10 BULLETIN 1403, L T . S. DEPARTMENT OF AGRICULTURE 
The corrected numbers corresponding to this 7:4:2:2:1 geno- 
typic ratio from the Bozeman F 2 data of 752 plants are 340 : 172 : 
88 : 96 : 56. The calculated on the above ratio would be 329 : 188 : 
94:94:47. The deviations in each class are 11, 16, 6, 2, 9, from 
which the value of 0.42 for P indicates a very close fit. 
AWNEDNESS 
BifTen (2) was first to point out that the awnless condition of a 
wheat spike is dominant. Other early workers obtained similar 
results in the first generation and also found that in the second gener- 
ation awnless and awned plants occur in the single Mendelian ratio 
of 3:1 or of 1:2:1 when intermediates occur. Howard and 
Howard (11) were the first to record two factors in the inheritance 
of awns when they grouped all awned and awn-tipped classes as 
awned, which in comparison with awnless gave a 15 : 1 ratio. They 
thus concluded the awned condition to be dominant. 
Clark (5) has shown that in Kota-Hard Federation crosses two 
genetic factors did not entirely account for the breeding behavior in 
F 2 and F 3 after the material was classified into five classes; that is, 
(1) awnless, as Hard Federation; (2) apically awnletted; (3) awn- 
letted; (4) short awned; and (5) awned, as Kota. The F x represented 
class 2, apically awnletted, and in F 3 all F 2 classes segregated into at 
least four classes. Two genetic factors would explain the behavior 
of strains breeding true for classes 1 and 2 and also those for classes 
4 and 5, but an additional factor or factors would be necessary to 
account for the variation remaining. 
In the present study (pi. 2), in which Hard Federation is awnless 
(class 1+), Marquis is awnletted (class 3 — ), and F t apically awn- 
letted (class 2), the F 2 and F 3 material is separable into three classes, 
(1) awnless, (2) apically awnletted, and (3) awnletted. Class 1, 
awnless, usually is without awnlets in the apical portion of the spike, 
although, like Hard Federation (1 +), it sometimes has a few awnlets 
1 to 2 milhmeters long. Class 2, apically awnletted, has awnlets 2 
to 20 millimeters long at the apex of the spike, but rarely extending 
to the central and basal portions. Class 3, awnletted, has awnlets 
from 3 to 40 milhmeters long, the shorter occurring at the base of 
the spike and the length increasing toward the apex, where many 
exceed the length of the awnlets on Marquis (3 — ) by 10 to 20 milh- 
meters. It is seen from Plate 2, A and B, that selections of the hybrid 
have a greater awn development than Marquis. 
The data by classes, obtained in F 2 at Bozeman and Moccasin in 
1923, are given in Table 7. Only normal plants are included in this 
study. 
The data given in Table 7 show segregation into the three awned- 
ness classes for 12 ¥ 1 families, of which 6 were grown at Bozeman and 
6 at Moccasin and of which 3 represent reciprocal crosses at each 
station. The results from reciprocal crosses at the two stations do 
not show significant differences. At Bozeman the Hard Federation X 
Marquis families in which the awnless Hard Federation parent was 
the female, have a slightly higher percentage of awnless plants, and 
the Marquis x Hard Federation families in which the awnletted Mar- 
quis parent was the female, have a slightly larger percentage of awn- 
letted plants. At Moccasin the same relationship existed for the 
