256 ORGANIC AGRICULTURAL CHEMISTRY 



sugar, malt sugar, starch, inulin. Carbohydrate material is 

 also further metabolized into fat and, with the assistance of 

 nitrogen, mostly in the form of nitrates, in the plant's soil food, 

 into protein. 



All three of these organic products of photosynthesis and 

 metaboHsm, the carbohydrates, fats and proteins, serve as 

 plant cell food for the liberation of energy. They are also 

 stored as reserve food supply for the young plant or offspring. 

 In addition to this they are converted into building material 

 for the plant body, the most abundant substance of this 

 kind being cellulose, which forms the cell wall structure and 

 which impregnated with resinous compounds results in the 

 woody fiber of trees. 



As a net result of all of these reactions, in which chlorophyll 

 bodies, chlorophyll and enzymes play an essential part, the 

 plant builds up from simple compounds the complex organic 

 food constituents which possess the energy of the sun's rays 

 stored in potential form. Thus the plant manufactures its 

 own energy food which is used either to yield energy or to 

 build body substance. Not only, however, does it manufacture 

 its own energy food, but in excess of this it stores up a reserve 

 supply for its offspring. This reserve supply is often not 

 allowed to be used by the young plant, but the plant or some 

 part of it is used by animals as food. As animal food both the 

 reserve food in seeds, etc., and all of the other constituents of 

 the plant body are utilized to a greater or less extent. From 

 this food herbivorous animals wholly, and all animals in part, 

 obtain the energy necessary for their life process and the ma- 

 terial out of which their bodies are built, in this last the in- 

 organic foods also taking part. 



References, Section II 



Abderhalden, Lehrbuch der Physiologischen Chemie, 1909. 

 Atwater, Principles of Nutrition (U.S. Dept. Agr. Bui. 142), 1902. 

 Barthel-Goodwin, Milk and Dairy Chemistry, 1910. 

 Bayliss, Nature of Enzymes (Monographs on Bio-Chemistry), 191 1. 



