THE SOIL. 23 



Experiment Station Bulletins, Nos. : 



60 Delaware Cover crops as green manure. 



68 Illinois Methods of maintaining the productive capacity of 

 Illinois soils. 



125 Illinois Thirty years of crop rotation on the common 

 prairie soil of Illinois. 



184 Ohio The maintenance of soil fertility. 

 Books : 



Soils Burkett Orange Judd Co., New York City. 



The Soil King The Macmillan Co., New York City. 



Soils Fletcher Doubleday, Page & Co., New York City. 



The Fertility of the Land Roberts The Macmillan Co., New 

 York City. 



Bacteriology in Relation to Country Life Lipman The Mac- 

 millan Co., New York City. 



Soils and Fertilizers Snyder The Macmillan Co., New York 

 City. 



Soils Lyon & Fippin The Macmillan Co., New York City. 



