AUTHOR'S PREFACE 



IN 1895 I published a Danish work entitled Plantesamfund, 

 which was based upon lectures that I had delivered in the 

 University of Copenhagen. I never imagined that the book 

 would appeal to more than a few readers outside my audience, 

 and was therefore greatly surprised shortly after its publication 

 to receive from Dr. E. Knoblauch a request for permission to 

 prepare a German version of my book an act of courtesy, 

 since Denmark had not subscribed to the Bern Convention, 

 and my book was thus public property. Thanks to Dr. Knob- 

 lauch's energy the German edition was published in 1896. In 

 the short time available I found it impossible to introduce more 

 than trifling changes into his edition, and was forced to post- 

 pone the more important modifications that I contemplated. 



In 1902 the publishers, Gebriider Borntrager of Berlin, 

 issued a second edition of this German translation. It was 

 edited by Dr. P. Graebner. With this edition I had nothing 

 whatever to do. The book was unchanged as regards plan and 

 arrangement of the subject-matter. 



I had always entertained grave doubts as to the arrange- 

 ment of the contents of Plantesamfund. When I wrote it I had 

 no models to study ; mine was the first attempt to write a work 

 on Oecological Plant-geography, of which the very name was 

 then all but new. The present book is practically a new one ; 

 for, not only have I myself introduced a number of new features, 

 but I have also invoked the aid of the young Phyto-geographer, 

 Dr. M. Vahl, in order that he might deal critically with purely 

 geographical and climatic considerations. 



The following changes are amongst the most important that 

 appear in the book as it is now presented in English : 



Chapter II contains fresh subject-matter dealing with 

 growth-forms, as well as an entirely new classification of these. 

 The parts of the book referring to adaptations of water-plants 

 and land-plants have been combined to form Section III ; and 

 in the same section I have given my views on oecological 

 classification in a more comprehensive and detailed manner. 



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