FACTORS FOE YIELD AND QUALITY OF SPRING WHEAT 
41 
The variability of the hybrids in comparison with the parents as 
determined by coefficients of variability is as follows : 
Coefficient of variation 
F 2 hybrids 8. 194 ±0. 161 
Hard Federation 7. 994± .383 
Marquis 7. 171± .342 
These data show that Hard Federation is slightly more variable 
than Marquis, but this variability is due principally to the difference 
in their mean heights. The hybrids also are slightly more variable 
than Hard Federation, but they are not significantly more variable 
even than Marquis. 
In 1924, height notes were recorded for nursery rows of F 3 strains 
and parent checks grown at Bozeman, Moccasin, and Havre. The 
frequency data obtained are given in Table 38 and are shown graph- 
ically in Figure 8. 
Table 38. — Height in the F s generation of 678 Marquis-Hard Federation wheat 
hybrids, in comparison with 79 parent checks grown in nursery rows at Bozeman, 
Moccasin, and Havre, Mont., in 1924 
Number of rows 
Average height of row 
Bozeman 
Moccasin 
Havre 
F 3 
hybrid 
Hard 
Fed- 
eration 
Mar- 
quis 
F 3 
hybrid 
Hard 
Fed- 
eration 
Mar- 
quis 
F 3 
hybrid 
Hard 
Fed- 
eration 
Mar- 
quis 
16 inches . 
1 
2 
11 
24 
21 
38 
17 inches. 

18 inches 
1 
1 
19 inches. .... . . 
1 
2 
20 inches. ..... 
1 
21 inches.. 
2 
22 inches. 
41 i 3 
51 
1 
23 inches. . . 
4 
24 inches. .... ...... 
41 
21 
17 
6 
16 
5 
4 
1 
..... 
1 
25 inches. ... . _ ... 
1 
23 inches. . . 
2 
27 inches. ... 
3 
2 
1 
28 inches ... . . 
2 
29 inches. 
5 4 
9 J 1 
16 3 
30iaches. 
1 
31 itches. .. ... ..... 
32 inches 
25 
33 inches.. 
30 
:::::::: 
34 inches. ._. 
29 
39 
35 inctes. . . 
1 
2 
36 inches.. 
25 
21 
11 | 
9 ! 

37inchts._ 
2 
4 
2 
38 inche; 
4 
10 
6 
18 
30 
29 
34 
15 
4 
39 inches. 
4 
2 
3 
40 inches. ...... 
3 
41 inches.. 
2 
1 
42 inches.. . . 
43 inches. ..... .. 
4 
2 
2 
44 inches. . 
45 inches 
46 inches- 
Total... 
224 13 
34.3 1 28.9 
13 
37.9 
150 
42.5 
9 
39.9 
9 
43.4 
299 
22.8 
18 
22.3 
17 
Average height in 
inches. 
22.9 
The data give further evidence of the intermediate nature of the 
height of hybrids between that of the parents. 
The differences in height of both hybrids and parents at the three 
stations strikingly show the effect of environment on height. At 
