THE LIVING MACHINE BUILDING FACTORS. 211 



nomena which we wish to explain. But these are 

 not peculiar to the complicated machines. We can 

 discard all the apparent machinery of the animal 

 or plant and find these properties still developed 

 in the simplest bit of living matter. To learn 

 their significance, therefore, we have turned to 

 the study of the simplest form of matter in which 

 these fundamental properties are manifested. 

 This led us at once to the study of the so-called 

 protoplasm, for protoplasm is the simplest known 

 form of matter that is alive. Protoplasm itself 

 at first seemed to be a homogeneous body, and 

 was looked upon as a chemical compound of high 

 complexity. If this were true its properties 

 would depend upon its composition, and would 

 be explained by the action of chemical forces. 

 Such a conception would have quickly solved 

 the problem, for it would reduce living properties 

 to chemical powers. But the conception proved 

 to be delusive. Protoplasm, at least the simplest 

 form known to possess the fundamental life pro- 

 perties, soon showed itself to be no chemical 

 compound, but a machine of wonderful intricacy. 

 The fundamental phenomena of life and of 

 protoplasm have proved to be both chemical and 

 mechanical. Metabolism is the result of the 

 oxidation of food, and motion is an instance of 

 transference of force. Our problem then re- 

 solved itself into finding the power that guides 

 the action of these natural forces. Food will not 

 undergo such an oxidation except in the presence 

 of protoplasm, nor will the phenomena of meta- 

 bolism occur except in the presence of living 

 protoplasm. Clearly, then, the living protoplasm 



