158 ORGANIC AGRICULTURAL CHEMISTRY 



form their functions separately, but are united into different 

 tissues and organs, and the functions of the various tissues and 

 organs are very different. Thus, while as stated above the indi- 

 vidual cells are alike in their fundamental chemical processes, 

 the net result of the processes of all the cells, or, as we may 

 say, the predominating reaction, is distinctly different so that the 

 single plant bears little resemblance to the single animal. 



In the animal organism, particularly in the mature animal, 

 as we shall find, the two functions of food are practically re- 

 solved into one, for food material which is converted into body 

 substance is eventually oxidized for the production of energy. 

 Only a small part of the food is utilized to build body substance 

 which is not later oxidized, and this material is largely the in- 

 organic portion. The net result of the physiological processes of 

 animals or, as we may say, the predominating physiological 

 process of animals, is the utilization of food for the production of 

 energy and this energy is manifested as animal work or animal 

 heat. In the plant organism, however, the two functions re- 

 main more distinct. Only a small part of the food is utilized 

 for the production of energy. The greater part is built up by 

 means of this energy into body substance which becomes either 

 reserve food or structural material. The net result of the phys- 

 iological processes of plants is thus the formation of body sub- 

 stance. These distinctly different net results are correlated 

 with distinctly different physiological processes in plants and 

 animals which differentiate them from each other and which 

 we shall consider later as we study each kind of organism. 



With these distinct differences between plants and animals 

 which we shall discuss we must not lose sight of the fact, first 

 stated at the beginning of this chapter, that in their fundamental 

 reaction plant cells and animal cells are alike, and this funda- 

 mental reaction is the oxidation of the three organic food con- 

 stituents, whereby energy is liberated and this energy is the 

 energy of the life process. 



