240 



and I sliall liave occasion to refer to his work in the following 

 pages. LiNDMARK (1902), also, has made a few anatomical observa- 

 tions on the subject. 



It is beyond the scope of this paper to discuss more fully the 

 contradictory conclusions which previous authors have considered 

 might be drawn from their studies of Alpine plants; here it will 

 suffice for me to give the names of the contending parties (Bonnier, 

 Leist, Wagner and Laznuowski) in llie list of literature, and also 

 Stenstrom who has, in a very comprehensive manner, studied and 

 discussed the questions here under consideration. Quite recently 

 Schroeter (1904 — 08) has published some valuable observations 

 upon Alpine Saxifragas. The investigations of these authors have 

 been taken into consideration only in so far as they have touched 

 upon Arctic species. 



Here we are only concerned with those Arctic species which 

 have been partially investigated by Th. Holm and F. Borgesen. I 

 shall not enter more closely into the general and comprehensive 

 results which Børgesen gives in his paper. 



The specimens investigated by me are the following: — 

 Saxifraga aizoides L p. 266 



— Aizoon Jacq p. 280 



— cernua L p. 242 



— Cotyledon L p. 276 



— ßagellaris Willd p. 269 



— groenlandica L p. 261 



— hieraciifolia W. K p. 253 



— hypnoides L p. 258 



— nivalis L p. 250 



— oppositifolia L p. 285 



— rivularis L p. 246 



— stellaris L p. 255 



— tricuspidata Rottb p. 273 



These belong to six different sections. Common to all the 

 species is a leaf-venation which is either palmate or appears to 

 have been derived from the palmate type even in such divergent 

 forms as S. aizoides and oppositifolia, the relatively serrate and 

 entire leaves of which, with regard to venation and form, are 

 connected by gradually transitional forms (especially S. tricuspidata) 

 with the palmate leaf of, for instance, S. cernua. Moreover, 



