xii 



CONTENTS 



CHAPTER XIII. PURPLE BACTERIA AND THEIR BEHAVIOUR TOWARDS 

 LIGHT. 



91. Their Morphology 



92. Influence of the Individual 



Colours of the Spectrum 



PAGJt 

 III 



93. Assimilation and Oxygen Elimi- 

 nation 113 



CHAPTER XIV. CHROMOPAROUS BACTERIA PRODUCING BLUE, GREEN, AND 

 VIOLET COLOURING MATTERS. 



94. Blue Coloration of Milk . . 115 



95. Blue Coloration in Cheese . . 117 



96. The Fermentation of Indigo . 119 

 97. Varieties of Bacillus Pyocyaneus 



Bacteria producing Violet 

 Pigments . . . .121 

 98. Green Bacteria Green Colora- 

 tion of Cheese . . .122 



CHAPTER XV. PHOTOGENIC BACTERIA. 



99. The Genus Photobacterium . 123 | 101. The Luminous Bacteria as Tests 

 100. The Food Requirements of Phos- for Enzymes . . . .125 



phorescent Bacteria . . 124 | 102. The Phosphorescents . .125 



CHAPTER XVI. THERMOGENIC BACTERIA. 



103. Spontaneous Combustion . .127 



104. Spontaneous Heating of Hops . 128 



105. Tho Fermentation of Tobacco . 128 

 1 06. The Preparation of Burnt Hay . 129 



Section V. The Heat-Resisting Bacteria : Their Place in Nature and their 

 Importance in the Fermentation and Food-Stuff Industries. 



CHAPTER XVII. BACILLUS SUBTILIS AND ITS CONGENERS. 



107. Roberts' Heat Method . .131 

 108. Morphology of Bacillus Subtilis 132 

 109. Influence of the Mode of Nutri- 

 tion on the Form of Growth . 133 



134 



no. The Potato Bacilli . 



in. Bacillus Fitzianus Production 



of Alcohol by Fission Fungi 136 

 H2. Bacterial Content of the Soil . 137 



CHAPTER XVIII. ^BUTYRIC ACID FERMENTATION AND ALLIED 

 DECOMPOSITION PROCESSES. 



113. Anaerobiosis . . . .139 



6 114. Methods of Cultivating Anae- 

 robic Bacteria . . . .140 



9 115. Clostridium Butyricum (Praz- 



mowski) and Bacillus Buty- 



ricus (Hueppe) . . .143 



116. The Genus Granulobacter . . 145 



117. The Equation of Butyric Fer- 

 mentation . . .147 



118. The Fermentation of Cellulose . 148 



119. The "Betting" of Flax and 



Hemp 151 



120. The Rancidity of Fats . .152 



