THE RE-ACTIONS OF ORGANIC MATTER ON FORCES. 61 



ence of force that each portion of mechanical or other energy 

 which an organism exerts, implies the transformation of as 

 much organic matter as contained this energy in a latent 

 state. And on the other hand, it follows from the persistence 

 of force that no such transformation of organic matter con 

 taining this latent energy can take place, without the energy 

 being in one shape or other manifested. 



