882 



INDEX OF SUBJECTS 



Irrigation, influence of, on biological 

 activities in soil, 784 



Isocystis, 226 



Isolation, of algae (impure cultures) 

 from soil, 216 

 of algae (pure cultures) from soil, 216 

 of bacteria from nodules, 128 

 of nodule bacteria from the soil, 129 

 of protozoa, 320 



Isonchus, 349 



Isopoda in soil, 342 



Isopods, 354, 355, 357 



Julus, 355 



Jumping beetles, 361 



June bugs in soil, 361 



K 



Karleria, 1\1 



Kirchnerella, 233 



Koch's postulates as applied to study 



of soil bacteria, 6 

 Kraussia, bacteria in, 105 



Lacrymaria, 335 



Lactarius, 278 



Lactic acid, formation of, by bacteria, 



178, 410, 412, 414, 440 

 Lamellibranchiata, 359 

 Larvae of insects in soil, 359 

 Lathyrus, nodule bacteria of, 134, 



135, 136 

 Law of chance in counting bacteria, 24 

 Lead plant, nodule bacteria of, 137 

 Leaf glands, bacteria in, 140 

 Leaves, composition of, 428 



decomposition of, 684 



nodule formation in, 139 

 Lecithine, decomposition of, 485, 650 

 Lecythium, 332 

 Legume inoculation, 819 

 Leguminosae, mycorrhiza formation 



by, 274, 275 

 Lembus, 335 



Lens, nodule bacteria of, 135, 136 

 Lepidoptera, 356, 358 



Leptomyxa, 331 

 Leptothrix, 93, 287, 288, 402 



ochracea, 93, 95, 100 



Irichogenes, 93 

 Lespedeza, nodule bacteria of, 136 

 Leucine as a source of energy, 411 

 Levulans, decomposition of, 461 



synthesis of, by bacteria, 383 

 Life cycles, of bacteria, 57, 117, 130 



of protozoa, 324 

 Lignins, and their decomposition, 298, 

 429, 455-460 



as a source of humus in soil, 693 

 Ligno-celluloses, 429, 455 

 Lignoceric acid in soil, 671, 672 

 Lima bean, nodule bacteria of, 136 

 Limax amoebae, 330 

 Lime, influence of, on biological ac- 

 tivities, 530, 714, 743, 789 



requirement of soil, as determined 

 by growth of Azotobacter, 581 

 Limicolae in soil, 342, 353 

 Limonite, deposition of, 235 

 Linyphia, 355 

 Lionotus, 335 



Lipoids in the microbial cell, 382 

 Lithobius, 355 



Lithosphere, composition of, 624 

 Loliurn temulentum, mycorrhiza for- 

 mation by, 272 

 Loxophyllum, 335 

 Lumbricus, 352 

 Lupinus, composition of, 428, 596 



nodule bacteria of, 130, 134, 135, 137 

 Luzerne, composition of, 428 

 Lyngbya, 226 

 Lysine in soil, 479 



M 



Macro-actinomyces, 309 

 Macrobiotus, 354 

 Macrosporium, 256, 807 

 Magnesium carbonate-gypsum block, 



71 

 Magnesium, influence of, on biological 



activities in soil, 576, 789 

 transformation of, in soil, 664-665 

 Malate-glycerin agar, 291, 306 



