5() 



\vilh air currenls oller may involve ceitain constant diflerences in 

 the results. The maximum values oblained by me for Nasturtium 

 and Atriplex are also somewhat higher than those found by Giltay 

 ll898), Brown and Escombe (190;')), and Boyskn-Jensen (1918) with 

 the air-current melhod. 



My values loo somelimes diverge considerably from each other, 

 a fact which is probably due lo the lack of homogeneity in the 

 material. A greater number of experiments would ha ve rendered 

 possible a more accurate knowledge of the shape of the curve. 

 For my purpose, however, the experiments carried ont give suffi- 

 •cient information. 

 7 



6 



Fig. 3. Diagram showing the influence of different iutensities of light upon tlie 

 CO2 assimilation of Xasfnrfinni pnUistre. Atriplex hastatum shows a similar but 

 higher curve. 



The culminating point of the assimilation is reached in the plants 

 of my experiments at the following values: 



{Atriplex latifoliiim 8.1; mg. per 50 cm -per 18" perl,hour 



Sun-planls 



Shade-plants 



[Nasturtium paluslre 6.0 » 

 Oxalis Acetosella. 2.4 » 

 Melandriumvubrum I.7 » 



Circea alpina I.7 » 



Stellaria nemoruin I.45 » 



From the figures it clearly appears that the sun-plants have a 

 far greater po^ver than the shade-plants of ulilising the available 



' This value is possibJv .somewhat too low, since the highest light-intensity 

 employed in this series was 1:2. 



