500 
Journal of Agricultural Research 
Vol. XXVII, No. 7 
Table VIII .—Statistical constants for petal spot grade of the parental and the homozygous 
F 3 progenies grown in 1923 
Population. 
DOMINANT PARENTAL 
12- 13-23. 
12-13-2 . 
Combined. 
13 - 8-4 . 
13-8-17. 
Combined. 
DOMINANT F 3 
£1-3-12-14x12) 20-14. 
£1-3-12-14x12) 20-15. 
£1-3-12-14x12) 28-7. 
(1-3-12-14x12) 28-8. 
Combined. 
(3-2-4-1X13) 21-2. 
£3-2-4-1X13) 21-21. 
£3-2-4-1X13) 24-18. 
£3-2-4-1X13) 24-46. 
Combined. 
RECESSIVE PARENTAL 
1-3-12-14-2-23. 
1-3-12-14-2-25. 
Combined. 
3—2—4—!—22—1. 
3-2-4-1-22-27. 
Combined. 
RECESSIVE F 3 
£1-3-12-14x12) 20-19. 
(1-3-12-14x12) 20-24. 
£1-3-12-14x12) 28-32. 
£1-3-12-14x12) 28-49. 
Combined... 
( 3 - 2 - 4 - 1 X 13 ) 
1 21 - 16 . 
( 3 - 2 - 4 - 1 X 13 ) 
1 21 - 22 . 
( 3 - 2 - 4 - 1 X 13 } 
124 - 25 . 
£ 3 - 2 - 4 - 1 X 13 ) 
Combined... 
I 24 - 48 . 
Number of 
plants. 
! Mean. 
Standard 
deviation. 
16 
8. 0 ±. 05 
0. 28 
29 
8. 1 04 
•32 
45 
8 . 08±. 032 
.316 
27 
8. 2 ±. 04 
•34 
39 
8. 1 ±04 
•33 
66 
| 8 . 12±. 028 
.338 
25 
i 7. 5 ±. 06 
.41 
48 
j 7.9 ±.03 
.29 
34 
7-8 ±.04 
•38 
46 
7-9 ±-°4 
•36 
*53 
7. 84 ±. 021 
.385 
42 
8. 0 ±. 04 
.41 
46 
8. 1 ±. 03 
.28 
43 
8. 1 ±. 04 
.38 
4 i 
172 
8.4 ±.03 
8 . 14±. 019 
:Sfe 
28 
I. 9 zb. 07 
• 57 
26 
2.3 ±.09 
.67 
54 
2. 10±. 059 
.646 
26 
2. 1 ±.08 
•63 
2 5 
1. 8 ±. 07 
• 49 
5 i 
1. 97±. 056 
.590 
42 
1. 0 ±.05 
•52 
37 
1. 1 ±. 05 
.46 
48 
2. 0 db- 07 
.68 
47 
x -5 ±.05 
• 50 
174 
1. 45±. 035 
.690 
36 
2. 1 ±.06 
•55 
47 
0.9 ±.04 
.41 
34 
2. 0 ±. 07 
. 62 
29 
2. O ±. 08 
.67 
146 
1. 66±.042 
.747 
SEGREGATION IN THE FIRST GENERATION 
The data at hand indicate that there may have been a slight degree 
of segregation in F x although the evidence is not very conclusive, progenies 
of only two plants in each of the Fj progenies having been grown. Table 
IX gives, for each cross, the grades of the F x parent individuals, the 
means of the spotted and spotless classes in their F 2 progenies and the 
means of the dominant and recessive F 3 populations derived from each 
Fi individual. Each pair of plants selected in F x had differed by more 
than a half-grade. The differences between the corresponding F 2 
progenies are in the same direction but are smaller than in F x and are 
not significant or barely significant. The differences between the F 8 
populations are not only in the same direction as in Fj and F 2 but seem 
to be significant in all but one case. 
