8 THE NATURE OF LIFE 



imagination but we cannot at present 

 prove or disprove its correctness. If it 

 should one day turn out to be true it will 

 greatly widen the possibility of finding 

 appropriate conditions for the origin of 

 life. 



n 



GROWTH 



Leaving this riddle of the origin of 

 life, let us turn to another question of 

 equal importance. What new factor 

 entered into the universe with the first 

 appearance of life? We may perhaps 

 put this in a more concrete form by ask- 

 ing, How may we distinguish the living 

 from the dead? 



It may not seem very difficult to an- 

 swer this question but the matter is less 

 simple than might at first appear. As 

 an illustration let us take some dry 

 seeds. Their appearance does not tell 

 us whether they are alive or dead. Most 

 people if called upon to decide would 



