XIV CONTENTS 



PART II.— PHYSIOLOGY OP MICROORGANISMS (RAHN) 



DIVISION I, — Nutrition and Metabolism. (A Pew Paragraphs on 

 Protozoal Nutrition by Todd, revised by Tyzzer.) 



Introduction — Principles of nutrition and metabolism, energy supply of micro- 

 organisms ' . ... . . ."141 



CHAPTER I. — Pood of Microorganisms .... . . . 148 



The composition of the cell, — Kloisture, cell wall, cell contents. — Amount of food re- 

 quired. — Food for growth (sources of carbon, nitrogen, hydrogen, oxygen, minerals). 

 -—Food for energy, — Oxygen relations. 



CHAPTER II. — Products of Metabolism . is8 



The chemical equations of fermentations. — Physiological variations. — Products from 

 sugar, starch, cellulose, alcohols, organic acids, fats. — Products from nitrogenous 

 compounds, — Protein bodies, ptomains, urea, uric acid, hippuric acid, — Products' 

 from mineral compounds, — Oxidations, reductions. — Unknown products of physio-" 

 logical significance, — Pigments, aromatic substances, enzymes and toxins. — Factors 

 influencing the type of decomposition. — Rotation of elements in nature, — Carbon cy- 

 cle, nitrogen cycle, sulphur cycle, phosphorus cyde. — Physical products of metabo- 

 lism, — Production of heat, production of light. 



CHAPTER III. — Mechanism of Metabolism . 189 



General theory of metabolism, — Metabolism, katabolism and anabolism. — Intra- 

 and extra-cellular fermentation, — Decomposition of insoluble food, properties of 

 enzymes, enzymes of fermentation. — Classification of enzymes, — Hydrolytic en- 

 zymes (enzymes of carbohydrates, enzymes of fats, enzymes of proteins), coagu- 

 lating enzymes, zymases, oxidizing enzymes, reducing enzymes. — Additional remarks 

 on the relation of cells and enzymes. — Theory of katabolism. — Theory of anabolism, 

 — Interaction of anabolism and intra-cellular fermentation, reversibility of enzymic 

 action. ' 



DIVISION II. — Physical Influences 



CHAPTER I.— Moisture .... . 207 



Osmotic pressure (Plasmolysis), Salt and sugar solutions, colloidal solutions. — Des- 

 iccation, 



CHAPTER II. — Influence of Temperature . 213 



Optimum temperature. — Minimum temperature. — Maximum temperature.^Bio- 

 logical significance of the cardinal points of temperature. — End-point of fermenta- 

 tion. — Freezing. — Thermal deatG-point. — Resistance of spores. 



CHAPTER III. — Influence op Light and Other Ravs ... 222 



Fhototaxis. — X-rays. — Radium rays. 



CHAPTER IV. — Influence of Electricity . . 226 



CHAPTER v.— Influence of Mechanical Effects ... . 227 



Pressure. — Gravity. — Ajfitation. 



I 



DIVISION III.— Chemical Influences 



CHAPTER I. — Stimulation of Growth.- 230 



Chemotropism and chemotaxis. 



