1 8 THE STORY OF THE LIVING MACHINE. 



attempt to explain the phenomena of life we have 

 two entirely different problems. The first is mani- 

 festly to account for the existence of this machine, 

 for such a completed piece of mechanism as a man 

 or a tree cannot be explained as a result of simple 

 accident, as -the existence of a rough piece of rock 

 might be explained. Its intricacy of parts and 

 their purposeful interrelation demands explana- 

 tion, and therefore the fundamental problem is 

 to explain how this machine came into existence. 

 The second problem is simpler, for it is simply to 

 explain the running of the machine after it is 

 made. If the organism is really a machine, we 

 ought to be able to find some way of explaining 

 its actions as we can those of a steam engine. 



Of these two problems the first is the more 

 fundamental, for if we fail to find an explanation 

 for the existence of the machine, our explanation 

 of its method of action is only partly satisfactory. 

 But the second question is the simpler, and must 

 be answered first. We cannot hope to explain the 

 more puzzling matter of the origin of the machine 

 unless we can first understand how it acts. In 

 our treatment of the subject, therefore, we shall 

 divide it into two parts : 



I. The Running of the Living Machine. 



II. The Origin of the Living Machine. 



