[11] Kopeloff, N., “The Effect of Soil Reaction on Ammonification by Certain Soil Fungi,” Soil Sci., 1916, 1. [12] Lendner, A., “Les Mucorinées de la Suisse,” 1908. [13] Manns, S. F., “Fungi of Flax-sick Soil and Flax Seed,” Thesis, N. Dak. Agric. Expt. Sta., 1903. [14] McBeth, I. G., and Scales, F. M., “The Destruction of Cellulose by Bacteria and Filamentous Fungi,” U.S. Dept. Agric. Bur. Plant Indust., 1913, Bull. 266. [15] McLean, H. C., and Wilson, G. W., “Ammonification Studies with Soil Fungi,” N.J. Agric. Expt. Sta., 1914, Bull. 270. [16] Muntz, A., and Coudon, H., “La fermentation ammoniaque de la terre,” Compt. Rend. Acad. Sci. (Paris), 1893, 116. [17] Oudemans, A. C., and Koning, C.J., “Prodrome d’une flore mycologique, obtenue par la culture sur gelatin préparée de la terre humeuse du Spanderswoud, près de Bussum,” Arch. Néerland. Sci. Exact et Nat., 1902, s. ii., 7. [18] Ramann, E., “Bodenkunde,” Berlin, 1905. [19] Rathbun, A. E., “The Fungus Flora of Pine Seed Beds,” Phytopath., 1918, 8. [20] Remy, T., “Bodenbakteriologischen Studien,” Centr. f. Bakt., 1902, ii., 8. [21] Sherbakoff, C. D., “Fusaria of Potatoes,” N.Y. (Cornell) Agric. Expt. Sta., 1915, Mem. 6. [22] Takahashi, T., “On the Fungus Flora of the Soil,” Anns. Phytopath. Soc., Japan, 1919, 1. [23] Taylor, M. W., “The Vertical Distribution of _Fusarium_,” Phytopath., 1917, 7. [24] Thom, Ch., “Cultural Studies of Species of Penicillium,” U.S. Dept. Agric. Bur. Animal Indus., 1910, Bull. 118. [25] Waksman, S. A., (_a_) “Soil Fungi and their Activities,” Soil Sci., 1916, 2; (_b_) “Do Fungi Actually Live in the Soil and Produce Mycelium?” Science, 1916, 44; (_c_) “Is there any Fungus Flora of the Soil?” Soil Sci., 1917, 3; (_d_) “The Importance of Mold Action in the Soil,” Soil Sci., 1918, 6; (_e_) “The Growth of Fungi in the Soil,” Soil Sci., 1922, xiv. [26] Werkenthin, F. C., “Fungus Flora of Texas Soils,” Phytopath., 1916, 6. CHAPTER VIII. THE LIFE OF FUNGI IN THE SOIL. In the last chapter fungi were considered as so many specific but functionless units in the soil. Unless, however, they are regarded merely as inert spore contaminations from the air, a view which is now no longer tenable, their very presence implies the existence of innumerable vital relationships between the organisms and their environment. From this point of view the studies treated in the previous chapter are but the necessary first steps to an understanding of the relation of soil fungi to living plants and of the part played by them in the soil economy. RELATION OF SOIL FUNGI TO LIVING PLANTS.