D. The Quantitative Measurement of the 

 Radiant Energy Incident on the Leaf and 



THE Utilisation of this Energy ... ... 138 



E. Assimilation in Relation to Radiant Energy 



OF Different Wave-Lengths ... ... 147 



Chapter VII. THEORIES OP CARBON ASSIMIL- 

 ATION. 



A. General Remarks 153 



B. Hypothesis of Baeyer 154 



C. Suggestion of van't Hoff 158 



D. Suggestion of Siegfried ... ... ... 159 



E. Theories of Willstatter 160 



Chapter VIII. CONCLUDING REMARKS 167 



LITERATURE CITED 170 



