VOLUME 20 

 NUMBER 9 



SEPTEMBER, 1917 



OONTAININQ 



The Indicator Significance of Native Vegetation in the Determination of 

 Forest Sites 

 Clarence F. Korstian 267 



The Adaptation of Truog's Method for the Determination of Carbon Diox- 

 ide to Plant Respiration Studies 

 A. M. Gurjar 288 



Environment of Seeds and Crop Production 



Byron D. Halsted and Earle J. Owen 294 



Books and Current Literature 298 



Notes and Comment » 301 



PTTBLI8HBD MONTHLY 



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Ent«r«d aa B«oond-clas9 matter March 9, 1912, at the post oflace at Baltimore, Maryland, under the Act of July 16, 1894 



