
1905.] On the Physiological Processes of Green Leaves. 55 
Table VI.—Influence of Reduced Illumination of Leaves of T'ropwolwm majus 
on Rate of Assimilation. Ordinary air used. 
A. Leaves exposed to sunlight which had passed through thin canvas screen. 
B. Leaves also under canvas screen, but light still further reduced by revolving 
sectors. | 
N.B.—The volumes of carbon dioxide absorbed by the leaves are corrected to the 
partial pressure of that gas in outer air. 





CO, 
| assimilated | Carbo- 
| _ | by leaf per} hydrate 
| ieee ee decimetre | correspond- 
Degen per hour in| ing to CO2 
| cubic in 
centimetres) grammes. 
(corrected). 
Experiment (1).— a ain Aer 
4/9/00. <A. Full illumination (under | 
BOVERI Hip us perstablods.- [nk eae 1692, |" 0*00212 
B. Half illumination (under | 
SIGL(S(23 00 ie RA | 20°3 2°029 = 0°00254 
Experiment (2).— | | 
18/9/00. A. Full illumination (under | | 
BCMGOM Pan cGei. nt oc oer acts 20-6 Legrg "0" 00240 
B. Half illumination (under | | | 
screen) ..... arte sheiuatseae io L9G 2°047 | 0:00256 
Experiment (3).— 
13/9/00. A. Full illumination (under | 
i 1) 212) 19 Na Pte | 24°2 1°926 0°00241 
B. Quarter illumination 
(under screen)!» {.....400: 22°°2 1°311 0°00164 | 




The following Table VII gives the results of a further series of experiments 
in which the rate of assimilation of detached leaves under free-air conditions 
was deduced from the ordinary half-leaf weighing method of Sachs, species of 
plants being taken in which the leaf-symmetry is especially well marked. 
The individual leaves were selected with great care to ensure as close a 
correspondence as possible between the two halves. 
