SOILS — FERTILIZERS. 817 



Some observations on humus formations in the soil, S. P. Kravkov {Dnevri. 

 XII. S'tezda Russ. Est.-Isp. i Vrach. [Moscow], p. 638; abs. in Zhur. Opytn. 

 Agron. (Russ. Jour. Expt. Landw.), 11 {1010), No. 5, p. 736). — An examination 

 of the composition of the ash of different plant residues and of the black ex- 

 tract of the underlying soil horizon showed a relationship which may be used 

 in classifying the humus formations. 



A contribution to the knowledge of the protozoa of the soil, T. Goodey 

 (Proc. Roy. Soc. [London], Scr. B, 84 {1011), Xo. B 510, pp. 165-180, pi. 1, 

 ■fig. 1). — Investigating further the suggestion of Russell and Hutchinson (E. S. 

 R., 24, p. 621) that protozoa limit the action of bacteria in soils with an accom- 

 panying decrease in ammonia production, the author found that " the ciliated 

 protozoa which are so characteristic a feature of cultures made from soil only 

 exist in the soil in an encysted condition. In consequence, they cannot func- 

 tion as the factor limiting bacterial activity in the soil." The investigations 

 dealt only with ciliated protozoa, not with amoebae and flagellates. 



Earthworms and soil fertility, Steglitz {FuhUng's Landw. Ztg., 60 {1911), 

 No. 15, pp. 538-5.'f2). — The author reviews the work of other investigators on 

 the subject, \\ith particular reference to the investigations by Russell (E. S. R., 

 24, p. 424), and takes the position that earthworms and other animal life have 

 an effect not only in bettering the physical condition of the soil and thus pro- 

 moting the production of nitrates, but that they render available as plant food 

 the mineral elements of the soil as well. 



The soil and the plant, E. J. Russell {Sci. Prog. Twentieth Cent., 6 {1911), 

 No. 21, pp. 135-152, pi. 1). — This is a review of American hypotheses of soil 

 fertility, particularly those of the Bureau of Soils, pointing out the outstanding 

 differences between them and those generally accepted. It is held that the 

 results of experiments at Rothamsted point to the great importance of the 

 nutritive function of the soil constituents and of added fertilizers, and the 

 theory that plants excrete toxic substances is not accepted. 



A bibliography of the literature is given. 



Field operations of the Bureau of Soils, 1908 (tenth report), M. Whitney 

 ET AL. ( U. 8. Dept. Agr., Field Operations of the Bureau of Soils, 1908, pp. 1^28, 

 pis. 8, figs. 38, maps 37). — This report contains a general review of the field 

 operations of the Bureau of Soils during 190S, by the Chief of the Bureau, 

 together with detailed accounts of the following surveys : 



Caribou area. Me., by H. L. Westover and R. W. Rowe; Livingston County, 

 N. Y., by M. E. Carr, G. A. Crabb, P. O. Wood, H. O. Tiffany, H. J. Wilder, and 

 E. O. Fippin; Montgomery County, N. Y., by O. Lee, jr., and C. Lounsbury; 

 reconnaissance survey of northwestern Pennsylvania, by H. J. Wilder, G. B. 

 Maynadier, and C. F. Shaw; Center County, Penn., by C. N. Mooney, C. F. 

 Shaw, L. A. Kolbe, H. H. Bennett, and R. T. Allen; Robinson County, N. C, by 

 W. E. Hearn, G. M. MacNider, and J. E. Turlington; Caswell County, N. C, 

 by W. E. Hearn and F. P. Drane ; Grady County, Ga., by H. H. Bennett et al. ; 

 Thomas County, Ga., by H. H. Bennett and C. J. Mann ; Lamar County, Ala., 

 by E. R. Allen and W. L. Lett ; Henry County, Ala., by G. B. Jones, E. S. Pace, 

 and H. L. Westover; Autauga County, Ala., by L. A. Hurst and C. S. Waldrop; 

 Colbert County, Ala., by W. G. Smith, C. S. Waldrop, J. C. Britton, and C. R. 

 Zappone, jr. ; Cullman and Bibb Counties, Ala., by W. E. Tharp and W. L. Lett ; 

 Calhoun County, Ala., by L. A. Hurst and P. H. Avary; Etowah County, Ala., 

 by W. S. Lyman and C. S. Waldrop; Jefferson County, Ala., by H. C. Smith 

 and E. S. Pace; Holmes County, Miss., by W. J. Geib; Monroe County, Miss., 

 by R. A. Winston, O. Lee, jr., A. W. Mangum, W. J. Latimer. A. E. Kocher, 

 and H C. Smith; Bienville Parish, La., by T. A. Caine, E. B. Watson, T. D. 



