XX LIST OF ILLUSTRATIONS. 



48. Crystals of bacteriopurpurin .121 



49. Carbon cycle 125 



50. Nitrogen cycle 126 



51. Sulphur cycle 127 



52. Action of light on bacteria 162 



53. Action of light on molds 163 



54. Action of light on mold colonies 164 



55. Chemotaxis . . I7 1 



56. Curve of disinfection . 174 



57. Influence of filtered water on typhoid fever and Asiatic cholera 197 



58. Section of sand filter 205 



59. Unglazed porcelain filters 207 



60. 61, 62. Location of wells on farm 209 



63. Construction of model well 210 



64. Trickling filter, sand filter, dosing tank, septic tank 223 



65. Septic tank 224 



66. Non-symbiotic nitrogen-fixing organism (B. pasteurianus) 270 



67. Non-symbiotic nitrogen-fixing organism (A zotobacter mnelandi) 271 



68. Ps. radicicola 275 



69. Section through root tubercle 276 



70,71,72. Influence of Ps. radicicola 279-281 



73. Section of cow's udder 297 



74. Bacterial colonies in dust from udder 300 



75. Bacterial colonies from cow's hair 301 



76. Bacterial colonies from dust of stable 302 



77. Small-top milk pails 305 



78. Ropy cream 324 



79. Ropy cream organisms 325 



80. Chart of Rochester milk supply 330 



81. Gassy cheese 348 



82. Cheese from lactic starter 349 



83. Influence of lactic organisms on casein degradation 354 



84. Swiss cheese 360 



85. Kepfir grain 368 



86. Bacteria of slimy wine 424 



87. Bacteria of wine diseases 426 



88. Vinegar bacteria 450 



89. Vinegar barrel 454 



90. Rapid process vinegar apparatus 457 



91. Ps. medicaginis 493 



92. Pear blight 497 



93. Crown gall 502 



94. Plasmodiophora brassica 504 



95. 96. Oidium albicans * 577 



97. Trichophyton tonsurans 578 



98, 99. Actinomyces bovis 581, 582 



100. Gonococci 587 



101. Bact. anthracis, thread formation boo 



102. Bact. anthracis, spores 600 



103. Organisms of anthrax in capillaries 602 



104. Bact. diphtheria 610 



105. Westbrook's types of Bact, diphtherias 611 



106. Bact. mallei 618 



107. Bact. pestis 625 



108. Bact. tuberculosis, branching forms 630 



109. Bact. tuberculosis, from sputum 630 



no. Bact. tuberculosis, in culture 631 



