Aug. 26, 1918 
Variation and Correlation in Wheat 
367 
Table II.— Means , standard deviations , and coefficients of variability for the characters 
of the wheat studied —Continued 
Standard deviations. 
Characters studied. 
1914 
1915 
1916 
1917 
Weight of individual seeds planted, 
mgm.. 
Number of days from planting to second 
leaf... 
10.079 ±0.278 
9. i99±o. 184 
8. 834±o. 160 
1.928± .035 
. 9S6± .017 
2*972± .054 
5 * 837 ± *105 
6. 226± . 112 
• 7I5± *012 
68.139 ± 1. 230 
6. 473± • 116 
• 766± .013 
15.320± .276 
9.601± . 173 
5. 674± . 102 
21. 5i4± * 388 
2. 2ii± .039 
7. 695±0.167 
1. 33odb .029 
. 8i4± .017 
2 . 079 ± *045 
6. 275± . 136 
6. 779 ± *147 
• 658± .014 
65. 755 ± *143 
5. 768± . 125 
• 652± .014 
18. 748 ± . 408 
xi. 584 ± *252 
7.383 ± ■ 160 
21. 041 ± .458 
1. 874 ± .040 
Height of plants at appearance of second 
leaf.cm.. 
Height of plants at six weeks.cm.. 
Height of tallest culm atmaturity. .cm.. 
Average height of culms at maturity, 
cm... 
Average length of spikes per plant, .cm.. 
Total length of culms per plant.... cm.. 
Total length of spikes per plant.. .cm.. 
Number of culms per plant. 
Total yield per plant.dgm.. 
Yield of straw per plant.dgm.. 
Yield of kernels per plant.dgm.. 
Number of kernels per plant. 
Average weight of kernels per plant, 
mgm. 
I. I20± .031 
3.282 i . 106 
8. 527 ± .275 
xx. 8 x 3 ± *325 
• 996± .027 
115.127±3.170 
10.861 ± . 299 
x, 628± .044 
26.930± . 742 
22.957± .632 
S. 378 ± -148 
27 - 753 ± *764 
3 - 999 ± *110 
1.094± .022 
3,88i± .078 
6. Ii8± . 122 
9. 638± . 192 
I.0o8± .021 
185.019 ± 3 -693 
15. g68± .319 
i.S 62± .037 
44.137± * 88r 
29.466 ± .588 
16.498 ± .329 
50. $84± i. ooi 
4.185 ± .084 
Characters studied. 
Coefficients of variability. 
Weight of individual seeds planted, 
mgm. 
Number of days from planting to second 
leaf. 
30.940±o. 930 
27. 8so±o. 597 
34. 27±o. 69 
14.01 ± . 26 
17.88± .33 
16.05 ± .30 
6.41 ± . 12 
7 * 35 i *13 
8.96± . 16 
30. 28± .59 
31.38± .62 
28.92 ± .56 
3 i* 90 ± .63 
31. 33± .62 
32. 79 ± .65 
31. io± . 61 
9 * 32 ± .17 
40. 47 ± 1. 02 
S* 05 ± .11 
13* ® 4 ± . 29 
13* 29 ± .29 
6 - 35 ± *14 
7*i 8± .16 
8. i9± .18 
24.451b .56 
24 * 44 ± *56 
22. gi± .52 
28.17± . 66 
28.05 ± .66 
28. 39 ± .67 
28.02± .66 
5. SO± .12 
Height of plants at appearance of second 
leaf.cm.. 
Height of plants at six weeks.cm.. 
Height of tallest culm at maturity., cm.. 
Average height of culms at maturity, 
cm. 
Average length of spikes per plant, .cm.. 
Total'length of culms per plant.cm.. 
Total length of spikes per plant.. .cm.. 
Number of culms per plant. 
Total yield per plant.dgm.. 
Yield of straw per plant.dgm.. 
Yield of kernels per plant.dgm.. 
Number of kernels per plant. 
Average weight of kernels per plant, 
mgm. 
I7*soo± .497 
I 4 v 570 ± *479 
9 * 799 i .316 
17* i6o± . 486 
13. osodb .366 
46.420±i. 529 
44. 640± 1.450 
45.150±i. 475 
56.8 io±2. 007 
57 * 97o±2. 064 
65* 95 °± 2 . 484 
49. 68o±j. 672 
37. i6o±i. 156 
20. 7io± . 431 
i6.670± .342 
5 * 38o± . 107 
9 * 790 ± .195 
12.090± . 245 
26.940± .575 
29-320± .634 
26. 690± . 569 
32 . 550 ± .715 
31* J50± .679 
40. 720 ± .938 
35 * 470 ± *792 
15. i8o± .310 
The somewhat higher productivity of the soil on which the plants were 
grown in 1914 and 1915, the conditions favoring or retarding growth 
each season throughout the four years, and the mean weight of the seed 
planted are very pertinent to the consideration of the variability of the 
plant characters. 
MEANS 
The mean for number of days from planting to second leaf was deter¬ 
mined for two years only. The greater number of days from planting to 
second leaf in 1917 as compared with 1916 was due to the lower temper¬ 
ature and drier weather during the period between planting of the seed and 
emergence in the former year. The means for height in centimeters at 
appearance of second leaf are 5.286 ±0.039 for 1915, 5.351 ±0.024 for 1916, 
6.247±0.251 f° r I 9 I 7> an d 6.401 ±0.044 for with no significant 
difference between the first two or the last two. One of the highest and 
