INDEX OF SUBJECTS 



877 



Deep colony procedure in isolation of 



bacteria, 168 

 Deflocculating agent in preparation of 



soil suspension, 22 

 Dematiaceae, 3, 255, 267, 443 

 Dematium, 244, 256 

 Dematophora, 264, '814 

 Denitrification, 180, 544, 550 

 Denitrifying bacteria, 60, 180, 185 

 cellulose decomposition by, 441 

 numbers of, in soil, 37, 38 

 Depths of soil, and distribution of 

 actinomyces, 40 

 and distribution of bacteria, 34-36 

 and distribution of fungi, 259 

 and distribution of protozoa, 48-49 

 Desiccation of bacteria, 583 

 Desmidium, 228 

 Desmodium canescens, nodule bacteria 



of, 136 

 Desmobacteriaceae, 78 

 Dextrans in the microbial cell, 383 

 Diaschiza, 351 

 Diatoms, occurrence of, in soil, 223, 



227, 645 

 Dicoccum, 256 



Dicyanodiamide, decomposition by 

 bacteria, 488 

 influence of, on nitrate formation, 533 

 Difflugia, 332 

 Difflugidae, 332 

 Diflugiella, 332 



Dihydroxystearic acid in soil, 463, 671 

 Dileptus, 335 



Dilution method for counting protozoa 

 in the soil, 45-47 

 for determining numbers of soil 



bacteria, 13, 27 

 in the isolation of soil bacteria, 55, 

 167 

 Dilutions of soil in preparation of 



plates, 18, 21-23 

 Dimastigamoeba gruberi, 330, 337 

 Dinoflagellata, 215, 230, 335 

 Dinornonas, 333 

 Diplogaster, 347, 349 

 Diplophrys, 332 

 Diplopoda, 355, 357 



Diptera, 356, 357, 358 



Direct method of isolation, of nitrite- 

 forming bacteria, 71 

 of soil bacteria, 55 



Direct microscopic methods for study 

 of soil bacteria, 7-11 



Discomyces, 287, 288 



Discomycetes, 251 



Discorea macroura, bacteria in, 140 



Disinfectants (see Antiseptics) 



Distigma, 334 



Distribution of bacteria in soil, 34-36 



Dorylaimus, 346, 348, 349 



Drying, influence of, on actinomyces, 

 299 

 of soil and increase of soluble salts, 

 742 



Dydymopsis, 278 



Dyer's greenwood, nodule bacteria of, 

 136 



Dyes, as indicators of oxidation-reduc- 

 tion potential, 542 

 influence of, on the growth of acti- 

 nomyces, 302 



E 



Earthworms, as carriers of pathogenic 

 bacteria, 805-806 



occurrence of, in soil, 3, 342, 351-353 

 Economic coefficient, 417 

 Ectotrophic mycorrhiza, 271, 280, 281 

 Edaphon, 642 

 Egg-albumin agar, 16 

 Eisenia, 352 

 Elateridae, 361 



Eleagnus, nodule formation by, 138, 139 

 Enchytraeids in soil, 342, 353 

 Enhytraeus, 354 

 Enchelys, 335 

 Endogone, 277 



Endotrophic mycorrhiza, 140, 271, 280 

 Energy, of ionization, 387 



liberation in microbiological proc- 

 esses, 422 



-nitrogen ratio, 506 

 Energy source for non-symbiotic 

 nitrogen fixation, 561-553, 569 



