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Contents 



PAGE 



Portrait of William Albert Setchell Frontispiece 



By PETER VAN VALKENBURGH 



William Albert Setchell: A Biographical Sketch .... xi 

 By T. H. GOODSPEED 



The Rate of Plant Migration i 



By O. W. ARRHENIUS 



The Origin of Crepis and Related Genera, with particular 

 reference to Distribution and Chromosome Relation- 

 ships 9 



By E. B. BABCOCK 



The Succession and Distribution of Cenozoic Floras 



around the Northern Pacific Basin 55 



By R. W. CHANEY 



The Origin of the Desert Climax and Climate 87 



By E E. CLEMENTS 



The Strand and Dune Flora of the Pacific Coast of North 



America: a Geographic Study 141 



By W. S. COOPER 



The Genetic Phy to geography of the Southwestern Pacific 



Area, with particular reference to Australia .... 189 

 By LUDWIG DIELS 



The Role of the Terrestrial Alga in Nature i95 



By E E. FRITSCH 



The Plant as a Metabolic Unit in the Soil-Plant System . . 219 

 By D. R. HOAGLAND 



5894 ;5 



