XXIV CONTENTS 



Chapter XIII 



SOIL PROTOZOA 



General morphology of protozoa. Physiology of protozoa. Media for the 

 cultivation of protozoa. Isolation of pure cultures of protozoa. Staining 

 of protozoa. Life history of protozoa. Occurrence of trophic and encysted 

 protozoa in the soil. Classification and occurrence of protozoa in the soil. 

 Importance of protozoa in the soil 311 



Chapter XIV 



THE NON-PROTOZOAN FAUNA IN THE SOIL 



Animal ecology as a whole and classification of soil forms. Methods of 

 study. Flatworms. Nematoda. Rotatoria. Annelida. Tartigrada. 

 Arthropoda. Arachnida. Myriapoda. Insecta. Mollusca. Influence of 

 environmental conditions on the invertebrate fauna of the soil. Economic 

 importance of the invertebrate fauna of the soil 341 



PART C. CHEMICAL ACTIVITIES OF MICROORGANISMS 



Chapter XV 



GENERAL PRINCIPLES OF MICROBIAL METABOLISM 



Metabolism as a whole. Chemical reactions in the microbial cell. Enzymes 

 of microorganisms. Reaction velocity. Growth, life and death of micro- 

 organisms. Chemical composition of the microbial cell 367 



Chapter XVI 



ENERGY TRANSFORMATIONS IN THE METABOLISM OF MICROORGANISMS 



Life and energy. Energy transformations by autotrophic bacteria. Energy 

 utilization from the oxidation of nitrogen compounds. Energy utilization 

 from the oxidation of sulfur and its compounds. Energy utilization from 

 the oxidation of iron compounds. Energy utilization from the oxidation of 

 hydrogen. Energy utilization from the oxidation of simple carbon com- 

 pounds. Heterotrophic utilization of energy by microorganisms. Aerobic 

 utilization of energy. Anaerobic utilization of energy. Efficiency of 

 energy utilization by heterotrophic microorganisms. Reduction of nitrates 

 and sulfates and energy utilization. Comparative amounts of energy 

 liberated by microbiological processes. Energy transformation in syn- 

 thetic processes. Energy transformation in the soil 384 



Chapter XVII 



CHEMISTRY OF DECOMPOSITION OF NON-NITROGENOUS ORGANIC MATTER BY SOIL 



MICROORGANISMS 



Composition of vegetable organic matter. Chemistry of celluloses. Mech- 

 anism of decomposition of cellulose by microorganisms. Decomposition 

 of cellulose by anaerobic bacteria. Decomposition of cellulose by aerobic 



