CONTENTS xi 



section paok 



5. Bacillus Radicicola ]79 



6. Mode of Entrance of Bacteria into Lequminods Plants 181 



7. Relation op Nitrogen-Bacteria to Lbouminous Plants 182 



8. Inoculation of Soil with. Bac. Radicicola 183 



CHAPTER XIV. 

 NITRIFICATION AND DENITRIFICATION 



1. Nitrification • 185 



-2. Nitrite-Bacteria 187 



3. Varieties of Nitrite-Bacteria 189 



4. Physiological Characteristics of Nitrite-Bacteria 191 

 6. Nitrate-Bacteria 192 



6. Morphological and Physiological Characteristics of Nitrate- 



Bacteria -. 193 



7. Nitrification in Nature 194 



8. Organisms that Reduce Nitrogen Compounds : Denitrification 195 



CHAPTER XV. 

 FERMENTATION 



1. Introduction- 198 



2. The Nature of Yeast- 199 



3. Examples of Fermentation 200 



Yeast-fermentation — malt fermentation — aoetio-aoid fermentation. 



4. Definition of Ferment and of Fermentation — Properties of 



Ferments 201 



5. Classification of Ferments 204 



6. Fermentations from which no Soluble Ferments have been 



Extracted 206 



Laotio-aoid fermentation — aoetie-aoid fermentation — butyric-aoid 

 fermentation — fermentations resulting in transformation of nitro- 

 genous organic compounds, of sulphur compounds, of propionic-, 

 citric-, and oxalic acids. 



