CONTENTS 



xv 



CHAPTER XXXI. THE FERMENTATION OF CHEESE, AND ALLIED 

 DECOMPOSITIONS. 



175. The Composition of Ripe Cheese 243 

 Conversion of Albumen into Fat 244 



| 176. Duclaux' Studies on Cantal 



Cheese 244 



177. Changes in the Bacterial Flora 

 of Ripening Cheese Aromatic 

 Cheese 245 



178. Pure Culture Ferments . . 246 



179. Natto and Miso . . . . 247 



180. The Normal Pitting of Cheese . 248 

 181. The Cause of Puffy (" Blown ") 



Cheese 249 



182. Cheese-makers' Recipes . . 250 

 183. Counteracting Puffiness in 



Cheese 251 



184. Bitter Milk and Bitter Cheese . 251 



CHAPTER XXXII. THE FERMENTATION OF UREA, URIC ACID, AND 

 HIPPURIC ACID. 



185. Urea, the Final Product of 



Animal Metabolism . . . 253 



186. Urea Unassimilable by Higher 



Plants 254 



187. Discovery of the Urea-Ferment 



by Pasteur . . . . 254 



1 88. Researches of P. Miquel . . 255 



189. Urase 257 



190. The Decomposition of Uric Acid 



and Hippuric Acid . . . 257 



CHAPTER XXXIII. THE FIXATION OF FREE NITROGEN BY BACTERIA. 



191. Accumulators and Consumers of 



Nitrogen 259 



192. Discovery of the Leguminous 



Nodules . . . .261 



193. Formation and Functions of the 



Nodules . . . . .262 



194. The Nodule Bacteria . . .264 

 195. The Bacteroids Infection 



Thread 266 



196. Clostridium Pasteurianum . . 269 



Section IX. Oxidising Fermentations. 

 CHAPTER XXXIV. THE IRON BACTERIA. 



197. Morphology of the Genera 



Crenothrix and Cladothrix . 272 



198. Physiology of the Iron 

 Smell of the Soil . 



Bacteria 



275 



CHAPTER XXXV. THE SULPHUR BACTERIA. 



199. Morphology of the Genus Beg- 

 giatoa Artificial Cultivation 

 ! cvero of the Sulphur Bcteiia . . 278 

 200. The Species of the Genus Thio- 



thrix 280 



201. Morphology of the Non-Fila- 

 mentous Sulphur Bacteria 

 Bacterio-purpurin . . . 281 



202. Physiology of the Su>phur Bac- 

 teria The Limanea . . 283 



CHAPTER XXXVI. THE NITRIFYING BACTERIA. 



203. The Recognition of Nitrification 



as a Physiological Process . 288 



204. Nifroso-Bacteria and Nitro-Bac- 



teria 289 



205. Nitrosomonas and Nitroso- 



coccus 290 



206. The Nitre-Bacteria . . .291 

 207. Assimilation in the Dark . . 292 

 208. Wall-Saltpetre and Plantation- 

 Saltpetre ... 293 



