[47] Moore, Benjamin, and T. Arthur Webster, “Studies of the photosynthesis in f.w.a.” (I.) “The fixation of both C and N from atmosphere to form organic tissue by green plant cell”; (II.) “Nutrition and growth produced by high gaseous dilutions of simple organic compounds, such as formaldehyde and methylic alcohol”; (III.) “Nutrition and growth by means of high dilution of CO2 and oxides of N without access to atmosphere,” Proc. Roy. Soc., London, 1920, B. xci., pp. 201-15.
[47a] Moore, B., Whiteley, Webster, T. A., Proc. Roy. Soc., London, B., 1921; xcii., pp. 51-60.
[48] Reinke, J., “Symbiose von Volvox und Azotobacter,” Ber. der d. Bot. Ges., 1903, Bd. xxi., S. 481.
[49] Russell, E. J., and Richards, E. H., “The washing out of Nitrates by Drainage Water from Uncropped and Unmanured Land,” Journ. Agric. Sci., 1920, vol. x., Part I.
[50] Schloesing, fils, and Laurent, E., “Recherches sur la fixation de l’azote libre par les plantes,” Ann. de l’Institut Pasteur, 1892, vi., pp. 65-115.
[51] Schramm, J. R., “The Relation of Certain Grass Green Algæ to Elementary Nitrogen,” Ann. Mo. Bot. Gard., 1914, i., No. 2.
[52] Wann, F. B., “The Fixation of Nitrogen by Green Plants,” Amer. Journ. Bot., 1921, viii., pp. 1-29.
CHAPTER VII.
THE OCCURRENCE OF FUNGI IN THE SOIL.
Note.—I am indebted to my late colleague Miss Sibyl S. Jewson, M.Sc., for permission to include unpublished data from our investigations on the soil fungi.
In 1886 Adametz,[1] investigating the biochemical changes occurring in soils, isolated several species of fungi. It was, however, only with the work of Oudemans and Koning,[17] in 1902 when forty-five species were isolated and described, the majority as new to science, that the real study of the fungus flora of the soil commenced. There is now no doubt that fungi form a large and very important section of the permanent soil population, and certain forms are found only in the soil. Indeed, Takahashi[22] has reversed the earlier ideas by suggesting that fungus spores in the air are derived from soil forms. The majority of investigations on this subject fall, perhaps, into one or more of three classes: (a) purely systematic studies such as those of Oudemans and Koning,[17] Dale,[5] Jensen,[9] Waksman,[25a] Hagem,[8c] Lendner,[12] and others, which consist in the isolation and identification of species from various soils: (b) physiological researches, such as those of Hagem[8c] on the Mucorineæ of Norway, or the many investigations on the biochemical changes in soils produced by fungi, such as those of Muntz and Coudon,[15] McLean and Wilson,[15] Kopeloff,[11] Goddard,[7] McBeth and Scales,[14] and others: (c) quantitative studies, such as those of Remy,[20] Fischer,[6] Ramann,[18] Waksman,[25c] and Takahashi,[22] which involve numerical estimates of the fungus flora in soils.