BUNT, 
15 
Table 12. — Results of the second experiment to determine the age or stage of seedling 
development at which the wheat seedling becomes noninfectible and the extent of 
infectible area of the plumule. 
[To be interpreted in connection with the diagrams of Figures 1, 2, and 3.] 
Letter. 
Number. 
Percentage of plants. 
Percentage of 
bunted heads. 
Series. 
Plants. 
Heads. 
Healthy. 
Wholly 
bunted. 
Partly 
bunted. 
In partly 
bunted 
plants. 
Total.) , 
f A 
20 
9 
8 
8 
20 
13 
16 
10 
22 
15 
14 
22 
28 
18 
12 
12 
25 
17 
18 
5 
23 
23 
15 
12 
17 
18 
10 
10 
16 
13 
15 
14 
12 
10 
16 
16 
13 
11 
- 396 
242 
223 
182 
296 
264 
295 
213 
260 
230 
205 
269 
266 
220 
172 
177 
315 
228 
201 
10J3 
286 
264 
234 
202 
231 
242 
185 
202 
246 
221 
204 
194 
208 
168 
212 
207 
208 
198 
10.0 
11.1 
25.0 

85.0 
46.1 

10.0 
72.7 
33.3 
28.6 
22.7 
92.9 
27.8 
8.3 

80.0 
35.3 
16.7 
20.0 
87.0 
56.5 
6.7 
33.3 
58.8 
22.2 

10.0 
93.7 
69.2 
46.7 
42.8 
66.7 
80.0 
43.7 
100 
30.8 
27.3 
35.0 
55.6 
25.0 
50.0 


62.5 
10.0 

13.3 
42.8 
50.0 

22.2 
41.7 
25.0 
4.0 
11.8 
38.9 


17.4 
26.7 
33.3 
11.8 
22.2 
30.0 
60.0 


26.7 
28.6 
8.3 

25.0 


54.5 
55.0 
33.3 
50.0 
50.0 
15.0 
53.9 
37.5 
80.0 
27.3 
53.3 
28.6 
27.3 
7.1 
50.0 
50.0 
75.0 
16.0 
52.9 
44.4 
80.0 
13.0 
26.1 
66.7 
33.3 
29.4 
55.5 
70.0 
30.0 
6.3 
30.8 
26.7 
28.6 
25.0 
20.0 
31.3 

69.2 
18.2 
59.4 
91.9 
84.3 
76.4 
26.2 
51.0 
75.1 
76.5 
61.3 
61.9. 
40.8 
81.7 
19.3 
65.9 
63.5 
63.4 
47.0 
73.9 
68.5 
71.6 
38.1 
38.1 
70.3 
82.5 
45.3 
39.1 
77.8 
77.5 
80.0 
27.5 
51.4 
74.0 
7.9 
74.2 
46.8 
70.2 
I 
B 
95.0 
C 
79.9 
b :::::.:.:.:..::. 
88.4 
(A 
7.1 
II 
B 
28.8 
C 
85.4 
Id : :...:...:. 
73.2 
(A 
17.7 
III 
B 
50.9 
ic 
50.7 
|d 
70.3 
(A 
2.3 
TV 
B 
55.0 
C 
70.3 
Id :...:.:.: 
73.3 
(A 
9.2 
V 
B 
57.9 
ic 
70.6 
Id 
62.8 
(A 
9.0 
VI 
B 
28.0 
C 
74.4 
Id :...:.:.:.:.... 
64.4 
(A 
29.0 
VII 
B 
37.6 
C 
82.2 
Id :.:.:.:.:::.:.:. 
85.6 
fA 
3.3 
VIII 
B 
10.0 
ic 
32.8 
ID 
41.9 
f A 
4.3 
IX 
B 
13.7 
jc 
44.8 
f A 

X 
B 
57.1 
55.2 
46.2 
[c 
46.0 
RELATION OF TEMPERATURE TO THE GERMINATION OF BUNT SPORES AND WHEAT 
KERNELS. 
To determine the importance of temperature as a factor in the 
germination of bunt spores and wheat, an extended series of cultures 
was conducted by the junior writer in the laboratory of plant patho- 
logy, Bureau of Plant Industry, where access was had to a compart- 
ment incubator. One additional culture was carried in a high- 
temperature incubator maintained at 29.1° C. 
The cultures in each case consisted of bunt spores and wheat 
kernels sown on the surface of finely pulverized moist basaltic soil 
obtained from Pullman, Wash. These cultures w r ere grown in Petri 
dishes and were incubated over a total period of 18 days in every 
case except culture 1 in incubator 1, which was maintained at an 
