6 
BULLETIN 971, U. S. 
DEPARTMENT OF AGRICULTURE. 
Table I. — Measurements of the tassel characters of the Ramosa and Gordo 
varieties of maize compared with those of the first and second generations 
of their hybrids. 
Measurements of length (centimeters) 
Parental 
Number of 
branches. 
Central 
designation. 
Entire. 
Branching Central 
Uppermost 
branch. 
Lowest 
spike 
index. 
space. spike. 
branch. 
Parents : 
Ramosa % .. 
32. 6± 0.37 
27.7±0.32 5.0±0.23 
1.8±0.05 
20. 7 ±0.31 
133. 7 ±3. 69 
15. 5± 0.58 
Gordo .-. 
30. 5 ±0.33 
5.1±0.14 ' 25.1±0.30 
15. 4± 0.21 
19. 4 ±0.30 
7. 0±0. 23 
83. 4± 0.43 
Combined Fi a 
47.7 
10.7 , 36.7 
21.8 
28.0 
14.4 
77.6 
Combined F2: 
Normal a 
38.4 
8.3 30.0 
17.3 
22.3 
13.4 
77.4 
Ramose a 
33.5 
21.7 10.3 
3.1 
17.6 
58.9 
30.8 
Mhl57Fi 
47.1 ±0.48 
10.7±0.28 36.3±0.55 
22. 0± 0.39 
26. 7 ±0.51 
17. 4± 0.83 
77. 0± 0.74 
Mhl58Fi 
48. 6 ±0.33 
10. 8 ±0.16 
37. 6 ±0.28 
22. 2± 0.26 
28. 4 ±0.30 
11. 8± 0.30 
77. 7 ±0.30 
Mhl59Fi 
46.0±0.43 
10.5±0.23 
35. 6 ±0.30 
21. 2 ±0.38 
28.1±0.45 
16.6±0.44 
77. 9 ±0.57 
Mhl57 F 2 : 
Normal 
33. 7 ±0.27 
8.4±0.12 
24.9±0.21 
14. 8±0. 18 
18. 4± 0.24 
19. 2± 0.35 
73. 6± 0-33 
Ramose 
29.6±0.39 
19.8±0.36 ! 10.0±0.25 
3.3±0.21 
14. 4± 0.26 
60. 4±0. 16 
32. 8± 0.69 
Mhl58 F 2 : 
Normal 
40.3±0.39 
8.0±0.26 
32.4±0.55 
18.3±0.46 
23. 4± 0.55 
10. 0± 0.37 
80.1±0.62 
Ramose 
35. 2± 0.50 
24.3±0.57 
10. 7±0. 30 
2.9±0.11 
18. 6 ±0.46 
55. 2± 1.51 
30.5±0.79 
Mhl59 F 2 : 
Normal 
43.2±0.39 
8.6±0.21 
34.5±0.37 
19. 5± 0.28 
27.3±0.44 
10. 3 ±0.32 
78. 7± 0.45 
Ramose 
38.1 ±0.66 
28. 2± 0.62 
10. 0± 0.60 
3.4±0.20 
22. 8± 0.72 
66. 0± 0.70 
25. 3± 1.24 
a The several progenies were combined for purposes of inspection only, and therefore the probable errors 
were not calculated. As a close inspection of the table will show, sister progenies differed in some charac- 
ters by amounts too large to be ascribed to chance, and therefore the combined progenies do not constitute 
a homogeneous population . 
When the ears 
were harvested the 
variability in the 
expression of the 
ramose character 
was even more 
striking. PI a n t s 
classified as ra- 
mose from the 
characteristics of 
their tassels bore 
ears which ranged 
in a continuous 
series from un- 
branched cobs to 
the typical rami- 
fied inflorescence 
(fig. 4). The un- 
branched ear pro- 
duced on a ramose 
plant is shown in 
Plates IV and V, 
while some of 
the intermediate 
stages are shown 
so 
\ 
\ 
1 
20 
/O 
fx&MOSE, 
r»" S 
HPi 
A/0/?/ff/9L 
J "1 
I, 
ITB t I LX_ 
\ 
■ l-n . 

Hi 
20 
30 
40 
so 
80 
70 
/ 
11 
Zl 
31 
ft 
SI 
61 
7/ 
Fig. 2. — Frequency distributions with respect to the cen- 
tral spike index in maize plants of the second hybrid 
generation of Ramosa-Gordo. The square marked with 
a cross represents a plant classed as ramose. 
