2 • ' INrRODUCTION 



Finally, as the agricultural problems with animals are largely 

 those connected with animal feeding and as plants are the main 

 food supply of domestic animals, we shall consider the distribu- 

 tion of food constituents in plants and the fundamental principles 

 of animal foods and feeding together with the use of certain 

 plants or plant products for other purposes than feeding, such 

 as the manufacture of various materials of economic value. 



Our entire study will thus be divided into three sections, as 

 follows : 



Section I. Systematic. The study of the composition, con- 

 stitution, character and relationship of the more important 

 organic compounds occurring in plants and animals. 



Section II. Physiological. The study of the chemical reac- 

 tions involved in the fundamental processes of living organisms, 

 in the utilization of food by animals and in photosynthesis in 

 plants. 



Section III. Crops, Foods and Feeding. The study of the 

 distribution of food constituents in agricultural crops and the 

 principles of animal foods and feeding. 



