Historical Plant Geography — xi — Foreword 



(Bot. Rev. 8: 195-246, 1942); and I. M. Johnston on the "Floristic Significance of Shrubs 

 Common to North and South American Deserts" (Jour. Am. Arb. 21: 356-63, 1940). 

 The affinities of the vegetation of the northern interior plains have been discussed in papers 

 by Raitp: " Phytogeographic Studies in the Peace and Upper Liard River Regions, Canada" 

 (Contr. Am. Arb. 6, 1934); "Botanical Investigations in Wood Buffalo Park" (Nat. Mus. 

 Can. Bull. 74, 1935). 



There have been but few papers in recent years on the historical plant geography of the 

 North American Cordillera. Problems in the alpine flora of the more northerly areas were 

 dealt with in part by Hulten ("History of Arctic Biota, etc."); and the arctic affinities of 

 the alpine flora of the central Rockies were treated somewhat earlier by Theodore Holm 

 in "Contributions to the Morphology, Synonymy, and Geographic Distribution of Arctic 

 Plants" (Rept. Can. Arct. Exped., 1913-1918, 5: pt. B, 1-139, 1922), and in "The Vege- 

 tation of the Alpine Region of the Rocky Mountains in Colorado" (Mem. Nat. Acad. Sci., 

 Wash. 19': 1-43, 1923). G. N. Jones had discussed the phytogeography of the Olympic 

 Mountains of Washington in "A Botanical Survey of the Olympic Peninsula, Washington" 

 (Univ. Wash. Publ. Bot. 5: 1-286, 1936). A recent paper by Herbert L. Mason, on the 

 "Distribution History and Fossil Record of Ceanothus" (in "Ceanothus", by M. Van 

 Rensselaer, pp. 281-303, Publ. Santa Barbara Bot. Gard., 1942), contains a summary of 

 some current ideas on the history of Cordilleran floras. 



The genetical approach to problems of migration and area has been adequately sum- 

 marized very recently by G. L. Stebbins in "The Genetic Approach to Problems of Rare 

 and Endemic Species" (Madrono 6: 241-58, 1942). These views were put into practice on 

 a regional floristic scale by Hult;6n in his "Arctic and Boreal Biota, etc." (see above), and 

 their implications for all students of the boreal American flora have been suggested by 

 Raup in "Botanical Problems, etc." (see above). 



Botanical aspects of the theory of continental drift have been almost entirely neglected 

 by American students. A brief paper (in abstract form) by W. H. Camp on " Continental 

 Displacement and the Origin of American Floras" (Proc. 8th Pan Am. Sci. Cong. 3: 193-4, 

 1942) is one of the very few that have appeared. Wuiff's review of European views on 

 the matter (Chapter X) should, therefore, be of great interest. 



Hugh M. Raup 



