THE PLANT AS A MACHINE 



Summary 



A plant, like a machine, responds either to the impact of 

 external forces, or to energy that is latent within. 



As the working efficiency of an engine is exhibited by 

 indicator-diagrams, so the physiological efficiency of a living 

 machine may be inferred from the character of its pulse- 

 records. 



Agencies which depress the physiological condition of a 

 tissue, also depress its responsive pulsation. At the death 

 of a tissue there is a permanent arrest of pulsation. 



