INDEX OF SUBJECTS 



887 



Noctuidae, 361 

 Nodularia, 224, 225, 226 

 Nodule bacteria, groups of, 136 



nitrogen fixation by, 122-140, 595 

 Nodule formation, by actinomyces, 310 

 by leguminous plants, 124, 128 

 by non-leguminous plants, 138 

 in leaves of plants, 105 

 Non-leguminous plants, inoculation of 



with nodule bacteria, 828 

 Non-spore forming bacteria, 4, 10, 



60, 141, 150, 153, 209 

 Non-symbiotic nitrogen fixation, chem- 

 istry of, 572 

 Nostoc, 220, 224, 225, 227 

 Nostococcaceae, 217, 223, 226 

 N uclearia, 331 

 Nucleic acids, 474, 479, 651 

 Nucleobacter, 651 



Nucleo-proteins, decomposition of, 651 

 Numbers of actinomyces in the soil, 

 39^2 

 of anaerobic bacteria in soil, 38 

 of anaerobic nitrogen fixing bacteria 



in soil, 110 

 of bacteria at different depths of 



soil, 34-36 

 of bacteria in different seasons of 



year, 31-34 

 of bacteria in manure, 29 

 of microorganisms in the soil, 3-50 

 of microorganisms in soil as an index 



of soil fertility, 711 

 of nitrifying bacteria in soil, 38 

 of nodule bacteria in soil, 129 

 of fungi in the soil, 42-44 

 of physiological groups of bacteria, 



36 

 of protozoa in the soil, 45-50 

 Nutrition of protozoa, 315 



O 



Obligate anaerobic bacteria, 160-163 

 parasitism, 804 



relation between mycorrhiza and 

 host plant, 283 

 Occurrence of heterotrophic bacteria 

 in soil, 145, 153 



Occurrence, of microorganisms in the 

 soil, 3-5 

 of trophic and encysted protozoa in 

 soil, 325, 329 

 Odor production by actinomyces, 303 

 Oedocephalum, 253 

 Oedothorax, 355 



Oidium, 3, 252, 287, 288, 289, 441, 775 

 Oicomonas, 318, 330, 334 

 Oligochaeta, 342, 351, 353, 357, 358 

 Oligonitrophilic bacteria, 104 

 Oligotricha, 336 

 Omnivagous nematodes, 346 

 Onobrychis saliva, nodule bacteria of, 



135 

 Onychodromus, 336 

 Oomycetes, 247, 275 

 Oospora, 252, 287, 288, 289 

 Orange-liquefying bacteria in soil, 27 

 Orcheomyces, 276 

 Orchidaceae, mycorrhiza formation by, 



271,276,277,283 

 Organic acids, decomposition of, 468 

 Organic matter, decomposition of, by 

 actinomyces. 309 

 decomposition of, by mycorrhiza 



fungi, 282 

 decomposition of, in manure, 498 

 decomposition of, in soil, 500, 510, 



673-681 

 influence of, on activities of micro- 

 organisms, 699 

 influence of, on autotrophic bacteria, 



61 

 influence of, on nitrification, 531 

 influence of, on nitrite and nitrate- 

 forming bacteria, 395, 528 

 influence of, on nitrogen fixation, 579 

 influence of, on oxidation processes, 



523, 540 

 influence of, on soil population, 768 

 nature of, 669 



role of, in soil processes, 625 

 transformation of, in soil, 669-707 

 utilization of, by algae, 231 

 Organic media for the cultivation of 

 algae, 222 

 nitrogen, nitrification of, 715 



