MATTER AND ENERGY 89 



mainly reductions ; in the animal there are 

 reductions as well as oxidations, but mainly 

 the latter. Both, as in processes of develop- 

 ment, convert potential into kinetic energy, 

 but in the plant the conversion is mainly from 

 kinetic into potential, while in the animal 

 the action is far and away a passage from 

 potential into kinetic energy. Thus the plant 

 world is, physiologically, the complement of the 

 animal world 



