296 
DONALD F. JONES 
all lines were again split up, but at that time the plants were nearing 
complete homozygosity and the lines which were separated after the 
Table i 
Susceptibility of Inbred Strains of Maize to Smut ( Ustilago zeae) 
Pedigree Number 
Plot I 
Plot II 
Plot III 
Number of 
Plants Grown 
Number of 
Plants Affected 
Percent Af- 
fected 
Number of 
Plants Grown 
Number of 
Plants Affected 
Percent Af- 
fected 
Number of 
Plants Grown 
Number of 
Plants Affected 
Percent Af- 
fected 
10-4-8-3-5-3-4-8-2 
29 
0 
0 
227 
0 
0 
10-4-8-3-5-3-4-5-2 
21 
I 
4.76 
223 
6 
2.69 
IO-3-7-3-9-7-5-I-I 
20 
0 
0 
242 
3 
1.24 
113 
0 
0 
10-3-7-3-9-7-5-4-2 
25 
0 
0 
274 
2 
•73 
I -9- I -2-4-6-7-5-6-2 
31 
0 
0 
183 
0 
0 
84 
0 
0 
I-9-I-2-4-6-7-5-3-2 
17 
0 
0 
185 
I 
•54 
96 
I 
1.04 
1-7- 1-2-2-9-2- 1 -I -I- 1 
27 
0 
0 
86 
0 
0 
I-7-I-2-2-9-2-I-I-4-3 
19 
I 
5.26 
196 
I 
•51 
80 
0 
0 
I-7-I-I-I-4-7-5-2-I-I 
29 
0 
0 
224 
18 
8.04 
I-7-I-I-I-4-7-5-2-6-I 
16 
2 
12.50 
157 
15 
9-55 
I-7-I-I-I-4-7-5-4-7-I 
21 
3 
14.29 
211 
28 
13.27 
52 
3 
5.77 
I-7-I-I-I-4-7-5-4-5-2 
25 
3 
12,00 
215 
21 
9-77 
I-6-I-3-4-4-4-2-5-5-2 
20 
0 
0 
183 
0 
0 
26 
0 
0 
I-6-I-3-4-4-4-2-5-3-2 
27 
0 
0 
195 
0 
0 
I-6-I-3-4-4-4-2-4-I-3 
30 
0 
0 
211 
0 
0 
1-6- 1-3-4-4-4-2-4-4-2 
20 
0 
0 
200 
0 
0 
80 
0 
0 
seventh generation remained quite similar. So that for our purpose 
four distinct lines descending from one original variety and two lines 
from a different variety can be considered. 
These strains were grown in duplicate and some in triplicate plots 
in three rather widely separated parts of the same field in 1917. Since 
the same strains show about an equal amount of susceptibility or 
immunity in all three plots, it seems evident that the pathological 
Table 2 
Summary of Figures Given in Table i 
Percent of Plants Affected 
Total Number 
Pedigree Number 
Plot I 
of Plants Grown 
Plot II 
Plot III 
Total 
10-4-etC 
2.00 
1-33 
1.40 
500 
0 
•97 
0 
•74 
674 
0 
•27 
.56 
.34 
596 
1-7-1-2-etC 
2.17 
•35 
0 
•49 
408 
1-7-I-I-etC 
8.79 
10.16 
5.77 
9^79 
950 
1-6-1-3-etC 
0 
0 
0 
0 
992 
