68 BULLETIN 1403, U. S. DEPARTMENT OF AGRICULTURE 
data, corrected on the basis of F 3 results, also gave a close fit to that 
ratio. A 2-f actor genetic interpretation of the results was made on 
the basis of primary (A, a) and secondary (B, b) factor pairs. 
Brown glumes were dominant to white, and in the F 2 generation 
the deviations in numbers were not significantly different from the 
simple 3 : 1 ratio in any of the 12 ¥ ± families or in the several totals. 
In the F 3 generation the white-glumed plants all bred true and the 
brown-glumed plants either bred true or segregated in a 3 : 1 ratio in 
proportions which approximated the ratio of 1 : 2. 
Red kernels were dominant to white, and in the F, generation 10 of 
the 12 F x families segregated in numbers close to a 2-f actor 15:1 ratio 
and the two other families close to the single factor 3 : 1 ratio. In the 
F 3 studies of the 2-factor families the white-kerneled strains all bred 
true and the red-kerneled strains bred true or segregated in 3 : 1 or 
15 :1 ratios in proportions approximating a 7 :4 :4 ratio. 
Maturity studies were made from the dates of heading, dates of 
ripening, and the days between these dates or from the heading, 
ripening, and fruiting periods. 
In F 2 early heading was partially dominant, although there were 
no large early and no small late groups. The hybrids were signifi- 
cantly more variable than the parents. No earlier heading strains 
than Hard Federation were produced, but transgressive segregation 
for lateness of heading was found, as F 3 strains were obtained which 
were significantly later in heading than Marquis both at Bozeman 
and Havre. 
The time of ripening of the hybrids was nearly intermediate be- 
tween the parents' and not significantly more variable. Strains as 
uniform as the parents for the ripening period were obtained in the 
F 3 generation, some of which were as late or later in ripening than the 
Marquis parent. 
The average fruiting period of the hybrids was intermediate to 
those of the parents. Strains of short and long fruiting periods were 
observed which differed on the average by as much as 6.7 days at 
Bozeman and 8.1 days at Havre. One F 3 strain was obtained which 
was significantly shorter than that of Marquis at both stations, but 
no hybrids were found to have a longer fruiting period than that of 
Hard Federation. 
From F 2 and F 3 studies, all gradations between the parents were 
found in average height without significantly greater variability than 
in the parents. The respective heights of the parents have been 
approximately reached by F 3 strains but not exceeded significantly. 
Yields of F 2 plants on the average exceeded those of both parents at 
Bozeman but were less variable. Plant yields were studied in the 
F 3 generation at Bozeman where Marquis was the highest yielding- 
parent and at Havre where Hard Federation was the highest yielding 
parent. From a high-yielding F 2 plant an F 3 strain was studied which 
significantly outyielded both the Marquis at Bozeman and the Hard 
Federation at Havre. 
The crude-protein content of grain from F 2 plants was found inter- 
mediate between that of the parents and not significantly more 
variable. F 3 strains from the highest F 2 plants did not rank among 
the best crude-protein strains at Bozeman or Havre. High crude- 
protein F 3 strains were found less variable than low crude-protein 
strains. While strains of lower crude-protein content than Hard 
