Activating enzymes, 125 Active immunity, definition of, 251, 252 production of, 252 Activities of bacteria, importance of, 31 overproduction, of cells, 258 physiological, definition of, 87 in identification, 216 Acute coryza, 244 disease, 233 Adulteration of food, anaphylactic test in, 293 complement-fixation test in, 279 immunity reactions in, 255 precipitin test in, 269 Aërobes, facultative, 76 strict, 76 Aërobic, 76, 215 Agar, composition of, 179 gelatinizing temperature, 179 medium, preparation of, 179 melting point of, 179 plating in, 188 sterilization of, 180 Agent, chemical, for disinfection, 156-163 choice of, for disinfection, 164 physical, for disinfection, 131 Agglutinating group, 266 Agglutination, acid, 266 diagnostic value of, 266 in identification of bacteria, 266 macroscopic, 265 microscopic, 265 phenomenon, 265 Agglutinin, 265 absorption test for, 267 action of, 266 anti-, 270 antigenic action of, 270 bacterial, 265 chief, 267 co-, 267 function of, 266 normal, 266 partial, 267 relation to precipitins, 269 specificity of, 267 theory of formation, 265 use of, 266 Agglutinogen, 266 Agglutinoid, 270 Aggressins, 288 Air, bacteria in, 71 filtration of, 153 “germ-free,” 153 Albumin in bacteria, 84 Alcohol as antiseptic, 160 as disinfectant, 160 Alcoholase, 125 Alcoholic fermentation, 31, 100 Alexin, 271, 273 Algæ, relation to bacteria, 37 Alimentary tract as path of entrance, 246 Alkalies as disinfectants, 158 Allergic, 290 Amboceptor, 273 anti-, 275 co-, 274 in cobra, 275 formation of, 273 hemolytic, 278 partial, 274 in rattle snake, 275 specificity of, 274 theory of formation, 273 Amboceptorogen, 274 Amebic dysentery, 29, 35 Ameboid cells, 247 colonies, 224 Amino-acids, relation to green plants, 119 Ammonia, structural formula, 103 Ammoniacal fermentation, 32 _Amœba coli_, 29, 35 Amphitrichic, 46 Amylase, 124 Anaërobes, 76 cultivation, methods of, 188 principles underlying, 188 facultative, 76 isolation of, 190 relation to elements, 86 strict, 76 Anaërobic, 76, 215 acid, butyric, 99 acid fermentation, 98 bacteria, first discovered, 32 fermentation of polysaccharides, 95 Analysis of ash, 82 chemical, of tubercle bacilli, 85 Anaphylactic, anti-, 290 phenomena, 292 reaction, uses of, 293 Anaphylatoxin, 290 Anaphylaxis, 289 anti-, 292 antibodies in, 291 theory of, 290, 291, 292 ANAXIMANDER, 18 ANDERSON, 289 ANDERSON and MCCLINTIC, phenol coefficient, 165 ANDRY, 25, 33