Allen and Jolivette—Light Reactions of Pilobolus. 575 
former source of light. We found 10% of the sporanges on 
the left half of the field. On the right half only 22% were 
on the opening and 6% beyond it, but 62% were found be¬ 
tween the middle line and the new opening. The discharge 
of these sporanges evidently took place while the re-aiming 
was in progress. 
Table XL —Percentages calculated from table X. part 2. 
Fraction of total 
crop of sporanges 
in evening record. 
Left half of field. 
Right half of field. 
Left of 
opening. 
Opening. 
Right of 
opening. 
Left of 
opening. 
Opening. 
Right of 
opening. 
9:45. 
1 
0 
0 
.6 
20.5 
67.7 
11.2 
7:15. 
1 
.6 
0 
1.9 
36.0 
47.2 
1.2 
10:15. 
1 
8.0 
0 
2.0 
62.0 
22 0 
6.0 
7:30. 
1 
0 
1.5 
3. 
22.1 
55.9 
17.6 
8:00. 
1 
8.5 ! 
1 3.7 
12.2 
14.6 
45.9 
15.9 
10:00. 
% 
5.5 
8.3 
13.9 
27.8 
33.3 
11.1 
9:00. 
5 /t 
9.0 
23.2 
34.0 
10.7 
23.2 
0 
10:30. 
% . 
8.8 
14.7 
30.4 
12.7 
27.4 
5.9 
9:15. 
y 2 ■ 
10.3 
19.1 
27.9 
11.7 
. 26.4 
4.4 
8:30. 
% 
4.3 
2.1 
44.7 
10.6 
36.2 
2.1 
9:30. 
S /l6 
33.3 
6.7 
11.1 
17.7 
31.1 
0 
In six of the experiments, those namely in which the light 
was changed at 10:00, 9:00, 10:30, 9:15, 8:30, and 9:30, 
part of the sporanges were already discharged. 'Under these 
conditions, a considerable proportion of the remaining spo¬ 
ranges were about, to be fired at the moment the change was 
made and others were to be fired in a few minutes. Conse¬ 
quently, a larger proportion of the sporanges fired after the 
change were discharged in the direction of the original illum¬ 
ination. Large numbers, however, are found in the region 
between the openings, and a varying proportion reach the 
new opening. 
The 8 :30 experiment is typical. .Nearly half of the entire 
crop of sporanges was discharged when the light was changed. 
Of the remaining half, we found in the evening that 4% 
were to the left of the former opening, 2%* on it, 44.7% be¬ 
tween the left opening and the middle line of the field, 10% 
between the middle line and the new opening, 36% on the new 
opening, 2% beyond it to the right. Late as it was, very few 
