74 NOTES AND COMMENT 



of the board are H. H. Whetzel, Cornell University; F, D. Kern, The 

 Pennsylvania State College; E. C. Stakman, University of Minnesota; 

 H. P. Barss, Oregon Agricultural College; H. W. Barre, Clemson 

 College; G. H. Coons, Michigan Agricultural College; and G. W. 

 Lyman, U. S. Department of Agriculture. 



A bulletin entitled Life Zone Investigations in Wyoming (North 

 American Fauna No. 42) has been prepared by Mr. Merritt Cary. 

 The same lines of treatment are followed that have already been made 

 familiar by Mr. Gary's Biological Survey of Colorado, Mr. Bailey's 

 Life Zones and Crop Zones of New Mexico and other publications of 

 the Biological Survey. The life zones from Upper Sonoran to Arctic- 

 Alpine are described and their characteristic species of plants and 

 animals listed. A concluding section is devoted to notes on the distri- 

 bution of conspicuous trees and shrubs. Wyoming lies wholly above 

 an elevation of 4000 feet, about one-third of its area being in the Upper 

 Sonoran Zone and about one-half in the Transition Zone. The latter 

 zone is made to comprise regions dominated by grasses, by sage brush 

 or by western yellow pine. 



A revised and somewhat enlarged third edition of Russell's Soil 

 Conditions and Plant Growth has been issued by Longmans, Green 

 and Company ($2.00). The revisions are tol^e found throughout the 

 book but have taken place chiefly in the chapters on the Composition 

 of the Soil (designated Constitution of the Soil in the second edition) 

 and on the Relationship between the Micro-organic Population of the 

 Soil and the Growth of Plants. A new chapter has been added on 

 Colloidal Properties of Soil, dealing with the absorption of salts by 

 soils, the colloidal character of soil acidity, the formation of hard-pan, 

 and the relation of colloids to soil evaporation and to the biochemical 

 reactions taking place in the soil. The Selected Bibliography has 

 been increased by about 25 per cent. 



