Mar x9» 19*3 
Spore Germination of Ustilago Avenae 
581 
should be as uniform as possible. Duplicate mounts were placed at each 
temperature, and the experiment was replicated 15 times. Automatically 
regulated incubators furnished the constant temperatures to which the 
spores were subjected. At each observation the percentage of germina¬ 
tion of 400 spores was recorded for each cell. 
The results of a typical experiment are expressed in Table I, and 
Figures i and 2. The results of all the experiments are brought together 
in Table II. 
Pig. I. —^Average percentage of germination, and presence of sporidia, of Ustilago avenae, in 34 hours, as 
influenced by temperature of incubation, in ^periment 5. 
TablP I .—Average percentage of germination of chlamydospores of Ustilago avenae 
produced 5 months earlier, incubated at different temperatures, and recorded at successive 
intervals 
Temperature 
average. 
C. 
3.5^.- 
5 <... 
7.6-... 
11.4°... 
14.6®... 
16.9®... 
21.7®... 
25.8°... 
29.9®... 
35 - 0 °... 
Temperature range. 
2 . 6 ®- 
4.4°- 
6 . 4 °- 
io.o°- 
13.6®- 
16.1®- 
17.8®- 
19.7®- 
22.5®- 
28.4®- 
34 - 0 ° 
C. 
- 4.8® 
- 6.0® 
- 8 . 8 ® 
-12.5® 
' 15-9 
-18.5® 
-20.6 
- 23 - 5 ° 
-28.4® 
-36.0° 
Time. 
K 
Days. 
O 
O 
O 
O 
o 
o 
•7 
3-0 
1-3 
•5 
o 
Days. 
O 
o 
O 
• 7 
7.0 
14. o 
18. o 
29. o 
22 . O 
4.0 
O 
Days. 
O 
O 
O 
10 
22 
21 
27 
27 
33 
2 
O 
Days. 
O 
O 
2 
27 
27 
32 
27 
31 
4 
s 
6 
7 
8 
9 
Days. 
0 
0 
14 
27 
34 
Days. 
0 
•4 
18. 0 
Days. 
0 
2 
Days. 
0 
3 
Days. 
0 
8 
Days. 
0 
10 
3 
0 
