Development of Chlorophyll. 815 
from Saturday mid-day to early Tuesday morning’. This exposure for two 
successive days to diffuse light caused the leaves to become almost the 
deep green colour of the normal bean plant, though the stems remained pale. 
TABLE IV. 
Etiolated Shoot-tips of Vida Faba. 
No. of 
Reading. 
Grams of CO 2 
given out. 
Illumination. 
Colour of Leaves. 
l 
•00 21 
Dark 
2 
•0021 
5 9 
3 
•0017 
Light 
4 
•0016 
99 
5 
.0015 
99 
6 
•0016 
n 
Distinct pale green 
7 
.0016 
99 
8 
* OOI 5 
Dark 
9 
•0016 
99 
10 
•0015 
Light 
11 
•OOIQ 
9 ) 
12 
• OOl8 
99 
Chamber containing shoots in north window for 60 hours 
including 34 hours of daylight. 
J 3 
•0001 
Light 
Almost normal 
14 
.0001 
99 
green 
15 
.0000 
99 
Normal green 
At last the power of photosynthesis was developed by this prolonged 
illumination, and upon replacing the chamber in the bath and determining 
Output 
of cq> 
IN CRAM5 
•ooa* 
*0020 
0018 
•ooie 
•OOI*- 
•001* 
*0010 
000a 
000 s 
• 000* 
0002 
•OOOO 
Time in 
Hours 
«— 
A 
> 
A 
V 
A 
f 
V 
"v 
X*S 
* 
t 
0 j 
, 
f 
1 
i 1 
4 1 
Z 14 16 
A 2 
0 2 
2 1 
4 lr 
irerval 
of 
SO H 
ours 
e 
4 a 
8 6 
8 9 
0 
including 34 Hour*Daylight 
Fig. 8 . 
the output of C 0 2 in the light, it was found that the whole of the C 0 2 of 
respiration was assimilated, and none escaped into the baryta tubes (Fig. 8). 
