S 16 
Irving.—Photosynthesis and 
TABLE V. 
Etiolated Shoot-tips of Vicia Faba. 
Exposed to daylight before the beginning of the experiment. 
No. of 
Reading. 
Grams of CO 2 
given out. 
Illumination. 
Colour of Leaves. 
1 
•0021 
Dark 
Pale green 
2 
•0017 
yy 
3 
•0015 
yy 
4 
•0016 
Light 
5 
•0022 
yy 
6 
•0020 
yy 
Grass green 
7 
.OOI9 
Dark 
8 
•0012 
yy 
9 
• OOII 
yy 
10 
•0012 
yy 
11 
•OOII 
>) 
12 
•OOIO 
>> 
13 
•OOO9 
Light 
.OOO9 
15 
•0007 
Darker green, but 
16 
•OOO9 
Dark 
not yet normal 
17 
•0007 
green 
18 
•0008 
yy 
19 
•0008 
yy 
20 
•OOO9 
” 
Experiment VII. 
In this experiment the etiolated Vicia Faba seedlings, while still growing 
in pots, were placed in the light (4p.rn.-10.30 a.m.) till they turned pale 
green. They were then cut and experimented upon as before (see Table V); 
Fig. 9. 
the temperature was 25 0 C. Here also there was no sign of diminished C 0 2 
output in the light, although at the second period of illumination the leaves 
