82 



PETROLOGY AND PEDOLOGY: 



of this kind may be in any climate and have a variety 

 of vegetation, depending on local environmental 

 conditions. The vegetation tends to represent 

 developmental stages of the more characteristic plant 

 cover of an area. Such serai stages are considered in 

 some detail later. The main a zonal soils are Litho- 

 sols, or thin, rocky soils of mountains, and Regosols, 

 either alluvial soils, or sandy, often alkali, soils. 



SELECTED READINGS 



Emmons, William H., et al., 1960. Geology: Principles and 



Processes. 5th ed. McGraw-Hill Book Co., New York. 

 Farb, Peter. 1959. Living Earth. Harper, New York. 



Lyon, T. L., H. O. Buckman, and N. C. Brady, 1952. The 

 Nature and Properties of Soils. 5lh ed. The Macmillan 

 Co., New York. 



Pearl, Richard M., 1956. Rocks and Minerals. Barnes and 

 Noble, New York. 



Russell, E. John, 1957. The World of the Soil. Collins, 

 London. 



Waksman, Selman A., 1952. Soil Microbiology. John Wiley 

 & Sons, New York. 



Yearbook of Agriadture, 1938. Soils and Men. U. S. Govern- 

 ment Printing Office, Washington, D. C. 



Yearbook of Agriculture, 1941. Climate and Man. U. S. Gov- 

 ernment Printing Office, Washington, D. C. 



Yearbook of Agncvlture. 1957. Soil. U. S. Government 

 Printing Office, Washington, D. C. 



