Parr.—The'Response of Pilobolus to Light . 
191 
Light 
Standard of 
Spectral 
Galvanometer deflex ¬ 
source . 
comparison . 
region . 
ions in mm . 
Tungsten 
±589 
± 54 ° 
385-270-115 
lamp 
(Green) 
460 — 355 = 125 
465 — 335 = J 3 ° 
460-335 = 125 
440 — 320= 120 
Average = 123 
±496 
(Blue) 
460 — 410= 50 
460—410= 50 
450-400= 50 
44 ° “ 39 ° = 5 ° 
Average = 50 
Galvanometer chang 
in sensitivity. 
>> 
±589 
365 — 165 = 200 
- 
(Yellow) 
360- 140 = 220 
385-165 = 220 
385-170 = 215 
Average = 214 
±470 
(Blue) 
335-282= 53 
387-328= 59 
ion in mm . 
400-345= 55 
415 - 345 = 70 
Average— 59 
277 
481 
133 
per cm . 2 
'350 
o -735 
2*480 
o*686 
Tables VI and VII give the data for the determination of the presenta¬ 
tion periods of Pilobolus in the different spectral regions. It was not 
deemed necessary to repeat here the periods of exposure longer and shorter 
than the ones which gave the final decisive results. 
Table VI. 
Light 
Series 
Colour . 
Wave¬ 
Time of exposure / Posi- 
% /«- 
Presentation 
source. 
No. 
length. 
2 tUljf * O • 
in mins. 
tive. different. 
time in min. 
Nernst 
Rn 1 
Red 
± 708 
24*6 
6 . 55 - 7*33 
= 78 
60 
40 
lamp 
Rn 2 
99 
23*1 
4 23 - 5*39 
= 76 
0 
100 
Rn 3 
99 
99 
24*0 
4.51-6.11 
= 80 
93 
7 
78 
R 11 
99 
± 667 
2 4*3 
6.13-7.28 
= 75 
0 
100 
R 12 
99 
3 > 
25-7 
4.05-5.21 
= 76 
88 
12 
R13 
99 
n 
24*0 
4.04-5.2 1 
= 77 
100 
0 
76 
On 1 
Orange 
± 631 
24*0 
4.36-5.51 
= 75 
64 
46 
On 2 
99 
24*0 
5 * 53 - 7*°5 
= 72 
0 
100 
On 3 
n 
99 
25*0 
4.55-6.12 
= 77 
90 
10 
75 
O 13 
92 
± 612 
26*3 
5.56-7.08 
= 72 
0 
100 
0 16 
99 
99 
24*5 
4 -I 8 - 5.33 
= 75 
100 
0 
O 17 
93 
-99 
24*7 
7.56-9.09 
= 73 
52 
4 8 
73 
Ym 
Yellow 
± 589 
24*7 
4.18-5.30 
= 72. 
60 
40 
Yn 2 
99 
24-7 
5.12-6.22 
=70 
20 
80 
Yn 3 
»> 
99 
25*0 
458-6.12 
= 74 
90 
10 
72 
Y 19 
± 585 
24*8 
7.55-9.05 
= 70 
0 
100 
Y 2.0 
JS 
99 
24*8 
6.01-7.15 
= 74 
100 
0 
Y26 
99 
99 
24*4 
7.06-8.18 
= 72 
50 
5 ° 
72 
G 8 
Green 
± 54 ° 
24*6 
7.50-9.00 
= 7 o 
100 
0 
G 10 
99 
99 
26*8 
6.51-7-56 
= 65 
0 
100 
G 11 
99 
99 
24*3 
5 - 34 - 6 . 4 3 
= 68 
33 
66 
69 
