THE SIMPLER ORGANISMS 89 



up of a large amount of energy. Then the living substance 

 acts as a chemical engine, using the energy of these same 

 organic compounds, and in that use, reducing them again to 

 simpler ones. Here as elsewhere, neither matter nor energy 



MAX SCHULTZE 

 (1825-1874) 



"The father of modern biology." Physiologist; histologist* 



who first showed that protoplasm is the common 



basis of plant and animal life. 



is created or destroyed, but both are endlessly transformed. 

 The living body is constantly changing. It is only the con- 

 stancy of the stream of income and outgo that allows it 

 to present a semblance of an abiding presence. It is like 

 the chemical engine in that it uses fuel the food whose 



