June ii, 1917 
Hybrids of Zea ramosa and Zea tunicata 
391 
Table II .—Comparison of observed and expected ratios of the different classes of plants 
Number expected out of 
each 16. 
Gametic 
composition. 
Characters of plant. 
Expected 
number. 
Observed 
number. 
1. 
T'T'RR . 
Normal. 
} 61.2 
2. 
T'T'RR '. 
.do. 
u 
2.: 
TT'RR . 
Half tunicate. 
J 
1 . 
4. 
TT'RR' . 
.do. 
> 122.0 
121 
1. 
TTRR . 
Full tunicate. . 
) 
\ 61.2 
2. 
TTRR / . 
.do. 
6l 
1... 
TTR'R' . 
Tunicata-ramosa ....... 
J 
} 61.2 
2. 
TT'R'R' . 
.do. 
64 
1. 
TTR'R' . 
Ramosa . 
J 
20. 4 
l6 
Total i§. 
326.0 
326 
When the character of the ear was considered, all the groups, with the 
exception of half and full tunicate, were perfectly distinct, with no 
doubtful individuals. 
CORRELATIONS BETWEEN TYPE OF PISTILLATE AND STAMINATE 
INFLORESCENCES 
The degree of correlation between the characters of the staminate and 
pistillate inflorescences may be judged from an examination of Table III. 
Table III .—Characters of the staminate and pistillate inflorescences of F 2 plants of Zea 
ramosa X Zea tunicata hybrid 
Character of staminate inflorescence. 
Character of pistillate inflorescence. 
Nor¬ 
mal. 
Half 
tuni¬ 
cate, 
glumes 
12-24 
mm. 
Full 
tuni¬ 
cate, 
glumes 
above 
25 mm. 
ROr 
tnosa. 
Tuni- 
caia- 
ramosa. 
Staminate 
inflores¬ 
cences 
destroyed. 
Total. 
Normal glumes, 5 mm. 
64 
64 
122 
Half tunicate, glumes 10 to 44 
mm. 
120 
2 
Full tunicate, glumes above 45 
mm or earless. 
A 
O 
49 
6 
59 
16 
Ramosa . 
*T 
16 
Tunicata-ramosa . 
37 
23 
A 
64 
*T 
Total . 
326 
Normal plants. —It will be seen that among normal plants the corre¬ 
lation is perfect. All plants classed as normal by the tassels proved to 
have normal ears, and vice versa. The number of normal plants was 64; 
the expected number 61.2. 
Half-tunicate plants. —As previously stated, the distinction be¬ 
tween half- and full-tunicate plants is not sharp. If one relies on the gen- 
