INDEX OF SUBJECTS 



Petroleum, oxidation of, by bacteria, 



97, 204 

 Phacus, 334 

 Phaeophyceae, 230 

 Phalansterium, 333 

 Phaseolus, nodule bacteria of, 134, 



135, 136, 137 

 Phenol, oxidation of, by bacteria, 205, 



465 

 Philodina, 351 



Phoma, 270, 276, 277, 281, 804, 807 

 Phormidium, 224, 225, 226 

 Phosphate-sulfur composts, 614 

 Phosphates, solubilization of, as a 

 result of direct bacterial action, 

 614, 652 

 solubilization of, as a result of inter- 

 action with acids formed by 

 microorganisms, 656-660 

 influence of, on nitrogen-fixation, 577 

 reduction of, in soil, 556 

 Phosphatides, synthesis of, by micro- 

 organisms, 382 

 Phosphorus compounds in soil, 625, 

 649 

 content of bacteria, 650, 651 

 organic in soil, decomposition of, 



650-652 

 requirements of soil, as indicated by 

 growth of Azotobacter, 577, 730, 

 731 

 transformation in soil, 650-660 

 Photosynthetic utilization of energy, 4 

 Phycomycetes, 247, 265, 275, 277 

 Phyllomitus, 333 

 Phyllomonas, 333 

 Phryganella, 332 

 Phycobacteria, 59 

 Phycocyanin, 215 

 Phycomycetes, 3, 259 

 Physiological activities as a basis of 



bacterial classification, 57 

 Physiological groups of bacteria, num- 

 bers of, in soil, 36 

 Physiology of anaerobic bacteria, 110, 



176 

 Physomonas, 334 

 Phytin, decomposition of, 651 



Phytoflagellata, 315, 335 

 Phytomonadinae, 334 

 Phytophthora, 247, 763, 807 

 Phytosterol in soil, 671 

 Picoline carboxylic acid in soil, 671 

 Pigment formation by microorganisms, 



303, 439 

 Pilobolaceae, 249 

 Pine needles, composition of, 428 

 Pinnularia, 227 

 Piptocephalis, 249 

 Pisum, nodule bacteria of, 130, 134, 



135, 136 

 Placocysta, 332 

 Plagiotricha, 336 

 Planarians, 345 

 Planobacillus nitrofigens, 121 

 Planococcus, 58 

 Planostreptococcus, 58 

 Planosarcina, 58, 208 



ureae, 208 

 Plant composition at different stages 

 of growth, 673 

 diseases caused by actinomyces, 809 

 diseases caused by bacteria found in 



the soil, 806 

 diseases caused by fungi found in 



the soil, 806-809 

 growth and nitrogenous decomposi- 

 tion products, 501 

 growth and saprophytic soil organ- 

 isms, 801 

 growth, influence of, on microbiologi- 

 cal activities in soil, 705, 792-800 

 infection as influenced by soil en- 

 vironment, 810 

 infection, as influenced by soil 



reaction, 813 

 nutrition, role of mycorrhiza in, 282 

 parasitic nematodes, 804-805 

 residues, decomposition of, by fungi, 



266 

 residues, influence of, upon plant 



growth, 516 

 secretions, 643, 692 

 Plants, non-leguminous, nitrogen-fixa- 

 tion by, 106 

 forming mycorrhiza, 273-275 



