WILLIAM A. SETCHELL' 



CONTAINING 



Some Mountain Plant Communities of Sandy Soil. Francis Ramaley 313 



Nutrient Requirement of the Potato Plant. Earl S. Johnston 329 



Root Contraction. Margaret B. Church 337 



Books and Current Literature 341 



Notes and Comment 344 



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Entered as eeeond-class matter March 9, 1912, at the post office at Baltimore, Maryland, under the act of July 16, 18W 



