374 University of California Publications in Agricultural Sciences [Vol. 3 



tions are unfavorable for the less resistant plants. Later Hilgard 

 and Loughridge 10 claimed that it is impracticable to attempt "a sat- 

 isfactory tabular classification in which each soil shall at once find its 

 pigeonhole prepared for it . . . because the subject matter is as yet 

 so imperfectly known." However, this does not dispute the justifica- 

 tion for making classifications for specific purposes or of specific 

 regions. With respect to this point there seems to be confusion. The 

 question is not whether soils can be classified at all or not, for every 

 observant farmer classifies the soil with which he is familiar, but 

 whether a satisfactory classification is possible over a large territory, 

 where soils are subject to the varying action of the important soil 

 forming agencies. 



Still another type of soil mapping is that of Hall and Russell, 

 which is given in their admirable Report on the Agriculture and Soils 

 of Kent, Surrey, and Sussex." 11 In this district the soils are largely 

 residual, and form quite distinct groups, depending upon the parent 

 geologic formation. These groups of soils, such as the Clay-with- 

 flints and the Thanet beds, have very definite agricultural properties ; 

 hence the treatment of all phases of agriculture upon each separate 

 group of soils. Hall and Russell 12 present an excellent discussion of 

 the methods of soil classification and the interpretation of the soil 

 analyses used in their study. Russell 13 gives a very similar though 

 briefer treatment. 



There are other more or less specialized classifications that have 

 been applied to local conditions and problems. As an example may 

 be cited Dicenty's work on grape soils. 14 



Various modifications of the above schemes of classifying and map- 

 ping soils are found in general texts on soils. 15 Nowacki 16 proposes a 

 curious system, Genera et Species Terrarum. It is in Latin terminology. 

 The genera are based on the quality of the soil, whether stony, sandy, 

 clayey, peaty, etc., and the species are dependent upon the quantities 

 of organic matter and clay. 



10 The Classification of Soils, Second Intern. Agrogeol. Conf., Stockholm, 1910, 

 p. 231. 



ii London, Bd. Agr. and Fish., 1911. 



12 Jour. Agr. Science, vol. 4 (1911), pp. 182-223. 



13 Soil Conditions and Plant Growth (London, Longmans, 1913), pp. 132-48. 



I* Die ampelogeologische Kartierung. First Intern. Agrogeol. Cong., Budapest, 

 1909, pp. 257-71. 



is Eamann, E., Bodenkunde, Berlin, Springer, 1911. 

 Mitscherlich, E. A., Bodenkunde, Berlin, Parez, 1905. 



isPraktische Bodenkunde (Berlin, 1892), pp. 130-80. 



