470 BIOLOGY. [BOOK vir. 



leaves fabricate albuminoidal substances is shown by the single 

 fact that the ascending sap conveys none to the chlorophillian 

 cells, and that nevertheless the descending sap carries some 

 away. 1 



The important chemical elaboration of the chlorophyllian cells 

 is therefore much less simple than at first sight it seems : it is 

 alike a labour of disseverment and of composition, of analysis 

 and of synthesis. _No doubt, if it is not completely certain that 

 solar radiation furnishes to the leaf all the mechanical energy 

 which the leaf displays, seeing that every atom and every mole- 

 cule possess affinities of their own, nevertheless it is the vibra- 

 tions emanating from the sun which give the impulse to all this 

 mechanical labour, and which are the principal agents thereof. 

 We are therefore justified in a very considerable degree in saying 

 that the plant treasures up solar radiation, that is to say move- 

 ment, which the animal afterwards utilises while transforming 

 it. The result of the combustions which are accomplished in 

 our tissues and wherever we make fire figure is truly the setting 

 at liberty of energies immobilised by the plant. All the acts, 

 all the movements, all the .facts of consciousness of animals and 

 of man are, at least in a considerable degree, transformations of 

 solar energy. 



But in this vast conception which contains so much truth, it 

 is needful that force should not cause matter to be forgotten. 

 In effect there is in the universe something besides dynamism. 

 No doubt, organised beings receive from the sun by the help of 

 interplanetary media impulsions, movements, which they utilise 

 and transform. But the substance of these beings has also its 

 own existence, its own sphere of activity. 



In reality there is in the universe neither force distinct from 

 matter, nor matter destitute of force. If the dynamik of the 



1 The ascending sap of the vine (the tears of the vine) does not, through 

 heat, yield albumin o:is precipitate ; through distillation a notable quantity of 

 gum is formed therein ; appropriate reactions reveal the presence of some 

 saline substances. 



