INDEX OF SUBJECTS 



Oribatidae, 355 



Ornithopus, nodule bacteria of, 134, 



135, 137 

 Orobus tuberosus, mycorrhiza formation 



by, 274 

 Orthoptera, 358 

 Oscillatoria, 220, 224, 226 

 Oscillatoriaceae, 223, 226 

 Osmotic pressure in the growth of 



microorganisms, 370 

 Oxalic acid, formation by micro- 

 organisms, 212, 410 

 Oxidase, 521 

 Oxidation processes in the soil, 520-541, 



717-720 

 Oxidation-reduction phenomena, 163, 



385, 520 

 Oxidative deaminization, 483 

 Oxidizing power of soil, 736 

 Oxygen absorption, by soil organisms, 

 163 

 from atmosphere, 170 

 Oxygen, influence of, on the growth of 

 anaerobic bacteria, 169 

 limit for the growth of bacteria, 161 

 removal in the cultivation of anaer- 

 obic bacteria, 169 

 requirement of actinomyce3, 299 

 requirement of protozoa, 314 

 supply of, in the growth of algae, 234 

 tension, in the growth of bacteria, 



160, 170 

 tension, influence of, on nitrate 

 formation, 535 

 Oxylricha, 336 

 Ozonium, 257, SOS, 813 



Pachybasium, 254 

 Palmitic acid, 411 

 Pamphagus, 332 

 Pandorina, 334 

 Pantostomatinae, 333 

 Paraffinbacterium, 204 

 Paraffin oil, decomposition of, by bac- 

 teria, 204, 465 

 Paraffin, oxidation of, 97, 204 



Paraffinic acid in soil, 671 

 Paramoecium, 314, 317, 318, 319, 335, 637 

 Parasitic fungi in soil, 709 



nematodes in soil, 348 

 Parasitism among soil microorganisms, 

 803, 804 

 of mycorrhiza, 283 

 Partial sterilization of soil, 743-749 

 Partridge pea, nodule bacteria of, 136 

 Pasture lands, insect fauna in, 356 

 Pavetta, nodule formation in leaves of, 



105, 106, 139, 804 

 Peanut, nodule bacteria of, 136 

 Peat, bacteria in, 785 

 Peat formation, 695 

 Pectins, 428, 446, 460 

 Pectin-decomposing bacteria in soil, 



38, 175, 203 

 Pectinobacter amylophilum, 203 

 Pectins, utilization of, by fungi, 242 

 Pecto-celluloses, 429 

 Pellia epiphylla, mycorrhiza formation 



by, 277, 804 

 Penicillium, 3, 238, 244, 251, 253, 258, 

 259, 260, 265, 275, 418, 443, 444, 

 454, 465, 642, 803 

 brevicaule, 303, 556, 652 

 chrysogenum, 495 

 expansum, 244, 382, 779 

 glaucum, 380, 382, 417, 652 

 intricatum, 495 

 italicum, 261, 637 

 luteum, 270, 604 

 variabile, 261 

 Penium, 229 

 Pennatae, 227 



Pentosans, decomposition of, by micro- 

 organisms, 446 

 determination of, 453 

 occurrence of, 452 

 Peptone-decomposing bacteria in 



soil, 37 

 Peranema, 334 

 Perhydridase, 521 

 Peritricha, 336 

 Peronosporales, 247 

 Peroxidase, 521 

 Petalomonas, 334 



