INDEX 



253 



Clostridium pastorianum, 24, 107 



Clostridium tetani, 40 



Cocci, 28 



Colloidal material in soil, 10 



Colpoda steinii, 40 



Composition of plant and animal 

 substances, 76-79 

 influence of, on decomposition, 78, 

 79 

 on products of decomposition, 

 93, 128, 133, 146 

 variation of, with growth, 78, 79 



Composting sulfur with rock phos- 

 phate, 171 



Cropping, influence of, upon bacteria 

 of soil, 59 



Cultivation of soil, influence of, on 

 soil microbes, 216, 217 



Cultural methods for the study of 

 microbes, 24, 50, 52-56 



Cyanamid, decomposition of, 129 



Cyanophyceae, 37 



Cycles of elements, 243-245 



Cystine, decomposition of, by micro- 

 organisms, 169 



Cytophaga lutea, 23 



D 

 Decay, 30 



Decomposition, of cellulose, 82-87, 

 89, 91 

 influence of nitrogen on, 84, 86 



factors affecting, 78, 79, 92 



of amino acids, 127-128 



of fats, 89-90 



of hemicelluloses, 81-82, 89, 91 



of lignin, 88-89 



of methane, 90 



of nitrogenous compounds, 126-135 



of organic matter, 14, 75-101, 204- 

 216 



of pentosans, 81 



of plant material, influence of com- 

 position on, 91-92, 143, 146 



of proteins, 126-129, 131 



of sugars and their derivatives, 79- 

 81 



products of, 75, 79-81 



Denitrification, 150-152 



importance of, in soil, 150-152 

 in manure, 151 



in soil, factors affecting, 151-152 

 Desiccation of soil, influence of, on 



fungi, 68 

 Diatomaceae, 37 

 Disease-producing organisms in soil, 



40-41 

 Distribution of microbes in soil, 



45-48 

 Dried blood, nitrogen assimilation 

 during decomposition of, 96, 

 133 



E 



Ectotrophic mycorrhiza, 197 

 Elective culture method, 55-56 

 Elements, abundance of, in earth's 

 crust, 4 

 and growth of microorganisms, 154 

 as plant nutrients, 15 

 Endotrophic mycorrhiza, 197 

 Enumeration of microbes, 24 

 Environmental conditions, influence 

 of, on nitrogen fixation, 111- 

 113 

 Environmental factors affecting de- 

 composition, 79, 87 

 effects of, on soil organisms, 74 

 Enzymes of microorganisms, 26 



Fat, decomposition of, 89-90, 164 

 Fats and waxes in plants, 78, 79 

 Fermentation, 30 

 Fertility, biological estimation of, 



234-240 

 Fertilizer practice, influence of, upon 



bacteria of soil, 59-60 

 Fertilizers, influence of, on soil 



microbes, 221-224 

 nature of effects of, on microbes, 



222-224 

 Filamentous fungi, 33, 35 

 Fixation of atmospheric nitrogen, 



104-126 

 Flagellates, 38, 39 



