IN THE ANIMAL ORGANISM. 203 



that of the oxygen separated in the organism of the 

 plant by the vital process. 



With the increase of these easily altered compounds, 

 in the flower and in the fruit, for example, the sum of 

 chemical force (the free manifestation of which, coun- 

 teracted by an equal measure of vital force, is employed 

 to furnish resistance) also increases. 



The plant increases in mass until the vital force in- 

 herent in it comes into equilibrium with all the other 

 causes opposed to its manifestation. From this period, 

 every new cause of disturbance, added to those pre- 

 viously existing, (a change of temperature, for example,) 

 deprives it of the power of offering resistance, and it 

 dies down. 



In perennial plants, (in trees, for example,) the mass 

 of the easily decomposable (azotized) compounds, 

 compared with that of the non-azotized, is so small, 

 that of the whole sum of force, only a minimum is 

 expended as resistance. In animals, this proportion is 

 reversed. 



During every period of the life of a plant, the avail- 

 able vital force (that which is not neutralized by 

 resistance) is expended only in one form of vital mani- 

 festation, that of growth or increase of mass, or the 

 overcoming of resistance. No part of this force is 

 applied to other purposes. 



In the animal organism, the vital force exhibits itself, 

 as in the plant, in the form of the capacity of growth, 

 and as the means of resistance to external agencies ; 



