- Absidia, 121.
- Acarina, 150, 151, 157.
- Acid formation by Fungi, 139.
- Acidity of soil, 17; effect on Actinomyces, 140; relation to nitrification,
36.
- Actinomycetes, 119, 134, 139.
- Aeration of soil, effect on bacteria of, 61.
- Agriotes, 150.
- Air supply in soil, 17.
- Algæ, agents causing disappearance of nitrate from soil, 12; associations of, in soil,
105, 106; blue green, 102 sqq. (see also
Cyanophyceæ and Myxophyceæ); colonisation of new ground by,
112; conditions of growth for, 101, 104,
107, 108; distribution of, 102, 104,
106, 109; economic significance of, 100,
102; filamentous, 106; flora of soil, 101,
112; formation of humus substances, 112; fragmentation of filaments,
107, 110; frequency of occurrence, 102 sqq.; glucose,
effect of, on growth, 108, 109; green, 104 sqq. (see
also Chlorophyceæ); importance in cultivation of rice, 113; numbers in soil of, 109,
110; nutrition of, 107, 108, 110;
producers, of organic substance, 100; pure cultures of, 107,
111; relation to gaseous interchange in soil, 113; relation to soil moisture,
112; seasonal changes in numbers of, 88; subterranean, 105.
- Alkaloids, as source of nitrogen for fungi, 138.
- Alternaria, 119.
- Amino-acids, formation of, by algæ, 108.
- Amino-compounds, decomposition of, by fungi, 136, 138.
- Ammonia, assimilation of, by bacteria, 33, 40, 45; effect of
partial sterilisation on soil content of, 66; formation in soil, 170; formation in soil
by bacteria, 32 sqq.; formation in soil by fungi, 135 sqq.,
141; influence of physical conditions on formation of, 137; property of attracting
Diptera, 159; utilisation by higher plants, 36.
- Ammonium sulphate, effect on fungi, 121, 126, 127.
- Anabæna, 102, 112.
- Annelida, 149.
- Antagonism of salts in soil, 60.
- Ants, 153.
- Arachnida, 150, 151.
- Arctic soil, bacterial flora of, 24.
- Areinida, 150, 151, 157.
- Armillaria, 132.
- Ascomycetes, 119.
- Aspergillaceæ, 136.
- Aspergillus, 119, 120, 135,
136, 138, 139.
- Azotobacter, 6, 41, 95, 96; assimilation
of nitrates by, 45; decreasing efficiency in liquid culture, 44; indicator of soil
acidity, 44.
- Bacillariaceæ, 100 (see also
Diatom).
- Bacillus amylobacter, distribution of, 24.
- Bacillus radicicola, 24, 46 sqq.; inoculation of soil with,
50; life cycle of, 47.
- Bacteria, association with algæ in nitrogen fixation, 111; anærobic respiration of,
37; effect of arsenic on, 61; cellulose destroying, 134; changes
in morphology in culture, 22, 47; classification of main groups,
23, 25; composition of cells of, 39; inverse relationship with
protozoa, 10, 79, 82 sqq.; isolation from soil,
21; methods of describing, 21; method of estimating numbers of, 53
sqq., 80; nitrogen fixation by, 110, 111; numbers in
relation to algæ, 110; numbers in soil, 52 sqq.; oxidation of hydrogen by,
27, 37; effect of partial sterilisation on, 8,
9, 66, 67; part played in soil fertility
by, 7; pure cultures, isolation by plating,
20; seasonal changes in numbers of, 59, 87 sqq.; effect of
salts on, 60; short time changes in numbers of, 11, 57,
58; effect of temperature on, 67; uneven distribution of, 57.
- Basidiomycetes, 119, 123, 132.
- Beets, attacked by Phoma betæ, 135.
- Boletus, 132.
- Botrytis, 122.
- Bryophyta, 100, 132.
- Bumilleria, 105.
- Calcium compounds in soil and fungi, 139.
- Carabidæ, 150.
- Carbohydrates, decomposition by bacteria, 26 sqq.; decomposition by fungi,
140; decomposition in soil, 168; effect on ammonia production in soil,
33; presence in algal sheath and bacteria, 111.
- Carbon, changes in amount in soil, 167; relationships of bacteria, 27;
relationships of fungi, 133; source of, for soil bacteria, 39; sources of, for soil
fungi, 139.
- Carbon dioxide, assimilation by algæ, 99, 107, 108;
assimilation by soil bacteria, 35, 36, 40.
- Carotin, in algæ, 100; formed by Spirochæta cytophaga, 29.
- Cecidomyidæ, 155.
- Cellulose, decomposition by bacteria, 27, sqq.; decomposition by fungi, 133,
134, 141; relation of nitrogen supply to decomposition of, 30;
decomposition in soil, 168; as source of energy for nitrogen fixation, 43.
- Centipedes, see Chilopoda.
- Cephalosporium, 120.
- Cephalothecium, 136.
- Chilopoda, 157.
- Chironomidæ, 155.
- Chlorella, 108.
- Chlorococcum, 105.
- Chlorophyceæ, 100.
- Chlorophyll, loss of, from algæ, 108.
- Ciliates, classification of, 72; cyst wall of, 73.
- Citric acid, formation of, by fungi, 139.
- Cladosporium, 119.
- Clamp connections in fungi, 119.
- Classification, of algæ, 100; of bacteria, 23, 25; of fungi,
131; of protozoa, 69 sqq.
- Climate, effect of, on algæ, 101.
- Clostridium, 41, 44; as fixer of nitrogen, 6.
- Coccomyxa, 104.
- Coleoptera, 150, 154, 155.
- Collembola, 150, 153, 154.
- Colletotrichum, 131.
- Commensals, 132.
- Conjugatæ, 100.
- Cortinarius, 132.
- Cotton, destroyed by fungi, 134.
- Counting, of algæ, 109; of bacteria, 53 sqq.; of fungi,
122; of protozoa, 77, 79, 80.
- Cresol, decomposition of, by bacteria, 22, 24, 31.
- Criteria, physiological, of fungi, 128.
- Crop growth, effect on fungi, 122.
- Cryptomonadineæ, 100.
- Cucumber leaf spot, 131.
- Cyanamide, decomposition of, by fungi, 136.
- Cyanophyceæ, 103 (see also Myxophyceæ and
blue-green algæ).
- Cylindrospermum, 102.
- Cysts, 68, 73, 74.
- Denitrification, by bacteria, 37; by fungi,
136.
- Desiccation, resistance to, by algæ, 106.
- Dew, relation to algæ, 101, 113.
- Diatoms, 104 sqq. (see also Bacillariaceæ).
- Dicyanamide, decomposition of, by fungi, 136.
- Dipeptides, formation of, by algæ, 108.
- Diplopoda, 157.
- Diptera, 150, 154, 155,
159.
- Disaccharides and fungi, 134.
- Earthworms, abundance of, in soil, 153; effect of, in soil,
13, 160, 175.
- Eel-worms, 149 (see also Nematoda).
- Elaphomyces, 132.
- Enchytræidæ, 149.
- Energy, laws of, 165; relationships of soils, 166; requirements of soil
organisms, 15, 16.
- Energy supply, relation of bacterial activities to, 25 sqq., 40,
44; sources of, for soil bacteria, 26 sqq., 40,
43; supplies of, for soil organisms, 111, 164,
167, 168.
- Environmental conditions in soil, 16.
- Eremacausis, 2.
- Ericales, 132, 135.
- Euglena, 99.
- Euglenaceæ, 100.
- Experimental error, in bacterial counts, 54; in fungal counts, 124.
- Farmyard manure, see Manure.
- Fats, used by fungi, 134.
- Fatty acids used by fungi, 134.
- Fertility of soil, views on, 2; effect of decomposition of plant residues on,
1, 165; effect of organisms on, 175.
- Filter paper, destruction of, by fungi, 133; destruction of, by Spirochæta cytophaga,
28.
- Fixation of nitrogen, discovery of, by Berthelot, 5; by bacteria, 40 sqq.;
by algæ, 110, 111; by mixtures of bacteria and algæ, 111; by
fungi, 135 sqq. (see also Nitrogen Fixation).
- Flagellatæ, 100.
- Flax sickness and fungi, 122.
- Formaldehyde, as agent for destroying fungi, 141.
- Fungi, control of, in soil, 139 sqq.; counting of, 122; distribution of,
in soil, 119 sqq., 127; fertilisers, effect of, on numbers of in soil,
126; as facultative parasites, 131, 132; fruiting bodies of,
123; destruction of hemicelluloses by, 133; individual, 122,
123; action on monosaccharides of, 134; mineral relationships of,
139; mycorrhizal, 132, 135, 139,
140; heterocyclic nitrogen compounds and, 138; occurrence in soil,
118; qualitative study of, 118; selective feeding of, 140;
specific determination of, 119.
- Fungi imperfecti, 119.
- Fusaria, 134.
- Fusarium, 119, 120, 122,
128, 133, 136.
- Gamascidæ, 156.
- Gases of swamp water (Paddy soils), 113.
- Gastrodia, 132.
- Gelatinous envelope of algæ, 109, 111.
- Geographical distribution of azotobacter, 41; of soil bacteria, 24; of protozoa,
75, 76; of soil fungi, 119, 125.
- Germination, of algal spores, 107.
- Glucose, use of, by algae, 108, 109, 111; use of, by moss
protonema, 109.
- Glycocoll, formation of, by algæ, 108.
- Granulobacter, 42.
- Greenland, bacteria in soil from, 24.
- “Grunlandmoor,” fungi in, 126.
- Hantzschia, 105.
- Hemiptera, 154.
- Heterokontæ, 100.
- “Hochmoor,” fungi in, 126.
- Hormidium, 104.
- Humus, the food of plants, 1; formation of, by fungi, 134,
141; formation of, in soil, 168; forest, 132; fungal hyphæ as
constituent of forest humus, 132.
- Hydrogen ion concentration, in soil, 17; effect on fungi of,
124.
- Hymenoptera, 150, 154.
- Insecta, 150, 157.
- Insects, numbers present in soil, 154.
- Invertebrata, definition of, 147; method of investigating, 148; groups
represented, 149; distribution in the soil, 151; dominant species and groups,
153; environmental factors of, 157; feeding habits, 156;
relation to agriculture, 160; relation to nitrogen cycle, 161.
- Iron compounds, oxidation by fungi, 139.
- Isopoda, 150, 151.
- Leguminosæ, association with bacteria, 46 sqq.; enrichment of ground by,
5.
- Lepidoptera, 150, 154.
- Life cycles, of bacteria, 22, 47; of protozoa, 72
sqq.
- Lime, effect on fungi in soil, 121, 126.
- Lyngbya, 112.
- Magnesium compounds, effect on fungi, 139.
- Manganese compounds, effect on bacteria, 61.
- Manure, farmyard, effect on algæ, 109, 110; effect on numbers of
bacteria, 60; effect on numbers of fungi, 126; effect on numbers of insects,
154, 155.
- Manure, Artificial, effect on fungi, 127.
- Manure, town stable, occurrence of disease organisms in, 132.
- Mastigophora, classification of, 71; species of, 71.
- Media, containing nitrates, chemical analysis of, 111; for counting soil bacteria,
54; for counting protozoa, 79; for counting fungi, 119,
123.
- Melanconium, 134.
- Melolontha, 150.
- Methane, oxidation of, by bacteria, 26, 27.
- Millipedes, see Diplopoda.
- Mites, see Acarina.
- Mollusca, 149,
157.
- Moniliaceæ, 136.
- Mucor, 120, 121, 136,
138.
- Mucorales, 121, 134.
- Mucorineæ, 118.
- Mycetophilidæ, 155.
- Mycorrhiza, 132, 135, 139,
140.
- Myriapoda, 150, 156.
- Myxophyceæ, 100 (see also Cyanophyceæ and
blue-green algæ).
- Naphthalene, decomposition of, by bacteria, 31.
- Naviculoideæ, 100.
- Nematoda, 149, 151, 157.
- Nitrate, assimilation by algæ, 105, 108, 111; assimilation
by bacteria, 33, 40, 44, 51; assimilation
by fungi, 136, 138; removal from soil, 12,
112, 171; variations in amount in soil, 11.
- Nitre-beds, 1.
- Nitrification, and bacteria, 34; chemical changes in, 171; and fungi,
136; energy supply in, 35; mechanism of, 1,
3; and soil fertility, 1, 3.
- Nitrites and fungi, 136; formation by bacteria, 34.
- Nitrobacter, 35.
- Nitrogen, changes in amount in soil, 167; cycle in soil, 161;
fixation by bacteria, 6, 40 sqq.; fixation by fungi, 135,
136, 141; fixation of, in clover plant, 5; increase by protozoa
of fixation of, 94, 95 (fig.); fixation sources of energy for,
43, 49; gain of, in soil, 174; in invertebrates,
162; loss of, by leaching, 112; loss of, from cultivated soils,
173; relationships of fungi, 135; relationships of algæ,
110-112; relationships of bacteria, 32 sqq.,
40 sqq.; relationships of insects, 162.
- Nitrosococcus, 35.
- Nitrosomonas, 35.
- Nodule Organism of the Leguminosæ, 6, 46 sqq.
- Nostocaceæ, 100, 101, 102,
107.
- Oligochæta, 149, 151, 153,
157.
- Oospora, 120.
- Orcheomyces, 132.
- Orchid cultivation and fungi, 132, 140.
- Orthoptera, 154.
- Oscillatoriaceæ, 100, 102.
- Osmotic pressure, influencing effect of salts on bacteria, 50.
- Oxalic acid, formation of, by fungi, 139.
- Oxidations effected by soil organisms; by bacteria, 26 et seq.; by fungi,
139.
- Oxygen, absorption by soils, 4.
- Partial sterilisation of soil, 8, 66 sqq.,
96, 178; influence of organic antiseptics, 177; limiting factor
in, 67, 68.
- Pectin, effect of, on fungi, 134.
- Pedras negras, 112.
- Penicillia, 134.
- Pentosans, effect of, on fungi, 134.
- Peptones, decomposition of, by fungi, 136, 138; source of nitrogen for algæ,
108.
- Periodicity, of protozoa in soil, 90 sqq. (fig.), 92
(fig.), 93.
- Phenol, decomposition of, by bacteria, 24, 25, 31.
- Phenylalanine, formation of, by algæ, 108.
- Phoma, 132.
- Phormidium, 106.
- Phosphates, availability of, influenced by bacteria, 52; by fungi, 139; effect on
bacteria, 46, 51, 60.
- Photosynthesis, 99, 100, 107, 110,
113.
- Phycocyanin, 100.
- Physical conditions in soil, 16.
- Physiological criteria, of bacteria, 22; of fungi, 128.
- Phycomycetes, 119.
- Phytophthora, 132.
- Plant disease, and fungi, 139.
- Plant residues, decomposition of, in soil, 168; influence of soil reaction on,
165; relation to soil fertility, 1, 165.
- Plasticity of fungi, 119.
- Plectonema, 106.
- Potassium salts, effect on bacteria, 60; influence of bacteria on the availability of,
52.
- Protein, decomposition of, in soil, 169; decomposition by bacteria, 32;
decomposition by fungi, 138, 140.
- Protococcales, 100.
- Protoderma viride, 105.
- Protonema of mosses, 100, 105, 106,
109.
- Protophyta, chlorophyll-bearing, 100.
- Protozoa, inoculation into soil of, 85 sqq.; isolation from soil, 69;
classification of, 69 sqq.; life histories of, 72 sqq.; species of, in
soil, 70 sqq.; distribution of, in soil, 74 sqq.; retention of, by soil,
78 (fig.); size of, 90; reproductive rates,
93; inverse relation with bacteria, 79
sqq.; presence of trophic forms in soil, 9; numbers of, in soil, 90,
96, 97; fluctuations in numbers of, 10, 81
(fig.), 82; external conditions, effect on, 82; seasonal changes,
effect on, 87 sqq.; weight of, 90.
- Pteridophyta, 132.
- Pythium, 132.
- Reaction of soil, 17.
- Reaction of soil, effect on bacteria, 36, 37, 46,
48, 61; effect on protozoa, 93, 94 (see
also hydrogen ion concentration).
- Relationships of Fungi, commensal, 132; mycorrhizal, 132; symbiotic,
132.
- Rhizopoda; classification of, 70, 71; species of, 70,
71.
- Rhythm, supposed in ammonification by fungi, 137.
- Rhizoctonia, 132.
- Rhizopus, 119, 120.
- Rice plant, aeration of roots, 113; physiological disease of, 113.
- Rock Phosphate as base for nitrifying organisms, 36.
- Rothamsted, Broadbalk plot 2 (Farmyard Manure) algæ, 109; fungi, 125,
127; Insects, 152.
- Rothamsted, Broadbalk plot 3 (Unmanured) algæ, 109; fungi, 120,
122, 127; Insects, 152.
- Rothamsted, Broadbalk Plots 10, 11, and 13; 122, 127.
- Rothamsted, Barnfield Plot 1-0 (Farmyard Manure), Protozoa, 80.
- Rothamsted, unmanured grass plot, 120.
- Russula, 132.
- Rusts, 119.
- Saccharomyces, 120.
- Saprophytes, facultative, 131.
- Saprophytism and algæ, 108, 110.
- Scenedesmus, 108.
- Seasonal fluctuations in numbers of soil organisms, 12, 87 et seq.,
125.
- Selective media, use of, in isolation of soil bacteria, 21.
- Serological tests, separation of varieties of B. radicicola by, 48.
- Slugs, see Mollusca.
- Smuts, 119.
- Snails, see Mollusca.
- Soil; comparison of, by volume, 17; effect of depth below surface on algæ, 101,
104, 109, 110, 113; effect of depth
below surface on insects, 151; effect of depth below surface on fungi, 121,
126, 127; effect of various treatments on fungi, 126,
127, 132; environmental factors in, 16; inoculation of, for
leguminous plants, 50; moisture (see Water supply); population, control of,
177 sqq.; population, methods of investigation, 10, 15;
sterilisation and fungi, 137, 138, 141 (see
Partial Sterilisation); stored, survival of algæ in, 107; type and fungi,
121, 126, 127.
- Soil conditions, effect on bacteria, 33, 36, 37,
40, 46, 48, 50, 59
sqq.; effect on protozoa, 82.
- Soil fertility, see Fertility of soil.
- Spicaria, 120.
- Spiders, see Areinida.
- Spirochæta cytophaga, 28, 43.
- Spore forming bacteria in soil, 23, 34.
- Spore, fungus, inhibition of formation, 123; presence in air of, 118.
- Standardisation of cultural methods for soil bacteria, 54 sqq.
- Starch, decomposition of, by fungi, 134.
- Stichococcus, 108.
- Straw; effect on nitrate production in soil, 33; manure, 29; rotting of,
30.
- Sulphur oxidation, by bacteria, 37; by fungi, 139.
- Symbiosis, of Azotobacter with other organisms, 42, 43, see also
Mycorrhiza and Nodule organism.
- Symphyla, 150, 151, 157.
- Symploca, 112.
- Tachinidæ, 150.
- Tannins, used by fungi, 134.
- Temperature of soil and fungi, 127, 140.
- Termites, 160.
- Testacella, 149.
- Thiospirillum, 37.
- Thysanura, 154.
- Thysanoptera, 154.
- Tipula, 150.
- Toluene, decomposition by soil bacteria, 31.
- Tolypothrix, 112.
- Trichoderma, 119, 120, 122,
134.
- Trochiscia, 105.
- Tropisms, 157.
- Ulothrix, 105.
- Ulotrichales, 100.
- Urea, by fungi, 136, 138.
- Uric acid, utilisation of, by fungi, 138.
- Vaucheria, 104,
106.
- Vitality, retention of, by algæ and moss protonema, 105, 107.
- Water; supply in soil, 17; and algæ, 112;
bacteria, 50, 61, 82; fungi, 127;
protozoa, 82.
- Wireworms, 155.
- Wood, decay of, 134.
- Woodlice, 150; (see also Isopoda).
- Yeasts, 138.
- Zygnema, 104.
- Zygorrhynchus mœlleri, 119, 120, 121.