58 Forestry Quarterly. 



predominating, 17%, (2) laterite, 9%. Equality of destruction 

 and transportation, 4%. Denudation predominating; (i) eolian 

 denudation, 2%, (2) glacial denudation, 25%. Accumulation 

 predominating; (i) glacial accumulation, 23%, (2) stream and 

 lake accumulations, \%, (3) fine eolian accumulations 13%, (4) 

 volcanic accumulations 1%. Dissected loess deposits 5%. One- 

 fifth to one-sixth of the total area of the United States is now 

 undergoing alluviation ; all the rest is being eroded. Shaler is 

 quoted in his statement that the soils of about 4,000 square miles 

 have been impoverished through wasteful agricultural methods, 

 representing a loss of food resources sufficient to support a mil- 

 lion people. The author adds that this figure seems gratifyingly 

 small besides the figure that would express the deplorable ruin 

 of the past quarter of a century of reckless timber cutting. Unless 

 the idea is included in the statement, he might better have added 

 the deplorable ruin of forest fires. 



In the ground covered, in the emphasis of the essential facts, 

 not to mention the clearness and crispness of statement, the 

 chapters (106 pages) on the soil constitute an excellent soil text- 

 book in themselves. 



The discussion of physiography is introduced by a chapter on 

 the physiographic, climatic and forest regions of the United 

 States as a whole, accompanied by numerous charts showing the 

 mean annual precipitation, percentage of rainfall in the growing 

 months, summer and winter temperatures, dates of killing frosts 

 in autumn and spring, the annual humidity of the air and the 

 forest regions. The necessity of the study of physiography for 

 a forester is emphasized by such expressions as these: "Phy- 

 siography is indispensable to the environmental study of organ- 

 isms of every kind, whether trees, men or bacteria. Soil, topo- 

 graphy and climate are positive forces in the development of 

 forests and the harvesting of forest products. They underlie the 

 main possibilities as well as the main limitations of nature." 



The author describes the topography, drainage, soils, rainfall 

 and forests of twenty-five physiographic regions, including some 

 broad subdivisions. Twelve of these are west of the Great 

 Plains. The lowlands of central and eastern United States con- 

 stitute six, and the highlands of the same region seven physio- 

 graphic types. The greater space is given to topographic de- 



