168 PLANT LIFE 



breaking up of the complex substances 

 constituting the dead bodies of other organ- 

 isms into simpler chemical compounds, and 

 sometimes even into their elements. They 

 utilise a certain amount of the energy thus 

 finally set free in building up the materials 

 of which their own bodies are constructed, 

 but the proportion of matter (and of energy 

 too) thus locked up again is extremely small 

 when compared with that which has been 

 liberated in the process. 



Regarded from this standpoint the sun is 

 seen to be the very fountain of life and power. 

 The complex materials which jostle each other 

 as they are borne down the stream of life 

 break down here, provide the power for 

 synthesis there, but on the whole are ever 

 losing more of their energy, for some is 

 continually dissipated as heat. Many of the 

 useless molecular fragments which drift out 

 of the stream of life are presently caught up 

 again at the fountain-head, the chlorophyll 

 machinery driven by the solar energy once 

 more draws them into the mill, there they 

 are broken up, are compounded with other 

 ingredients, and the whole turned out once 

 more as energy-containing carbohydrate. 

 Again the compounded matter re-enters the 

 stream of life, to part, little by little, with 

 the energy it contains. Some is destined to 

 reappear in vital units of almost infinite 

 complexity, the rest is utilised or lost in 

 various ways, and the broken and buffeted 



