6 BULLETIN 1403, U. S. DEPARTMENT OF AGRICULTURE 
Correlations here reported were determined by the product moment 
coefficient of correlation method in which r xv = — ^^±0.6745 — ?=— 
xy 
■yjn 
Correlation coefficients greater than three times their probable errors 
are here considered statistically significant. 
Plant selections were made in the F 2 and F 3 generations from their 
appearance in the field, their threshed grain, and from each frequency 
class for date of heading, date of ripening, fruiting period, height, 
yield, and crude-protein content. The dwarf plants introduced a 
possible difficulty in maintaining a random sample. The lack of 
evidence of linkage between dwarf ness and other characters, together 
with the few instances of linkage ever recorded in wheat hybrids, 
minimizes the importance of this, and the writers feel that the normal 
plants, as selected, fairly represent a random sample. 
SEGREGATION OF CHARACTERS IN THE F 2 AND F 3 GENERATIONS 
The Fj plants grown at Davis, Calif., in 1922 were all normal in 
stature, apically awnletted, brown glumed, and red kerneled. No 
further notes or comparative data with the parents were obtained 
in this generation. 
A study of individual plants for the principal contrasting characters 
and factors for yield and quality was made on the F 2 material grown 
at Bozeman in 1923 and for some of the characters on similar material 
grown at Moccasin in the same year. The study was continued on 
F 3 material grown at Bozeman, Moccasin, and Havre in 1924, to 
determine the inheritance and the environmental effect on the mate- 
rial under the different representative Montana conditions. 
The characters studied for their inheritance are dwarfness, awned- 
ness, glume color, kernel color, curledness of leaves, heading period, 
ripening period, fruiting period, height, yield, and crude-protein 
content of the grain. 
The reciprocal crosses were studied to determine the differential 
influence, if any, on the progeny. Dominance of the curled-leaf 
character appeared partially reversed in F 2 of reciprocal crosses. 
The studies made on this character will not be presented in this 
bulletin. The results of the studies of the other characters in the 
F 2 and F 3 generations follow in the order listed above. 
ETWARFNESS 
Dwarf plants appeared in F 2 progenies of all F x families of the 
Marquis X Hard Federation and reciprocal wheat crosses grown at 
Bozeman and Moccasin in 1923. At Bozeman some of the dwarf 
plants headed at a height of about 6 inches and matured seed. At 
Moccasin, however, only a few produced heads late in the season, 
and none of them matured seed. The dwarf plants which did not 
head were similar to the grass clumps first described by Farrer (7). 
From the results at the two stations it appears probable that both 
genetic and environmental factors were in part responsible for differ- 
entiation into the groups hereafter called dwarfs and grass clumps. 
At Bozeman there appeared in the F 2 progeny of six F 1 families 600 
normal plants, 114 dwarfs, and 38 grass clumps; at Moccasin, in the 
F 2 progeny of six other ¥ x families, there were 457 normals and 101 
