nfTEOBÏÏCTIOIf. 



i his paper has, like the preceding ones of the same series, a 

 two-fold purpose: the one to contribute to a belter knowledge of the 

 relation between the arctic plants and the conditions under which 

 they live, and the other to serve as a basis for future studies of a 

 similar nature. 



I think 1 have contributed towards the first-mentioned by 

 distinguishing two types in my material : an arctic and a temperate 

 one and by confining my representation to this main point, and 

 as regards the second I hope to have succeeded in some measure in 

 pointing out the future way towards a closer treatment of the 

 question. But on the whole my paper has, more and more, at- 

 tained the character of a preliminary sketch, in which also the 

 principles of my future works on this subject are laid open to 

 criticism. The cause of this is, among other things, that on working 

 up my subject I found that a material, collected several years ago, 

 could not serve one and every purpose; the new principles for 

 botanical treatment have outgrown the principles which determined 

 the collection of the material, and the application of this has be- 

 come more limited. In regard to ecological studies it will be 

 necessary in the future to form new principles for investigations 

 in Nature, as I have also had occasion to mention in the text. 



The material for investigation I have received partly from the 

 Botanical Museum in Copenhagen and partly from the "Riks- 

 museum" in Stockholm. The latter institution has very generously 

 placed its perfect and beautiful herbarium at my disposal. The 

 photographs have been taken by H. E. Petersen, Mag. Sc. The 

 illustrations were drawn mainly by Professor Edg. Warming several 

 years ago; on some points — all concerning morphology — I 

 have naturally found it necessary to add new ones. The deter- 



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