[Vol. 2 

 106 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



ing, especially in view of the most recent discoveries of fossil 

 arctic plants, and my own observations of the rock formations 

 in the west and north of Norway, that I have come to the con- 

 clusion that this iceless strip of coast was broader than I 

 formerly supposed, and extended to the extreme southern 

 point of Norway. In this respect my view is thus in perfect 

 accordance with that of Stejneger. 



As to whether there was an interglacial direct land connec- 

 tion between England and Norway, as Stejneger assumes, 

 I cannot express an opinion, but I do not, in any case, consider 

 it necessary for botanical reasons, although I am inclined to 

 believe that the assumption of Stejneger will prove to b s cor- 

 rect. On the other hand, I consider a post-glacial land con- 

 nection between England and Norway, concerning which 

 Stejneger himself is much in doubt, to be quite out of the 

 question. There is nothing that can be brought forward to 

 prove that previous to the post-glacial subsidence the land lay 

 high enough for any real land bridge between Norway and 

 England to exist. On the other hand, there are several facts 

 that go to show that the southern part of the North Sea has 

 lain higher than it now does, so that even considerable por- 

 tions that are now under the sea were clothed with forest. 

 This may possibly to some extent have diminished the distance 

 between England and Norway; but the deep Norwegian Chan- 

 nel outside the coast of Norway has certainly been in existence 

 ever since the Last Glacial Period. 



But a land connection is not necessary to explain why the 

 few species of plants that Norwav and England have in com- 



mon, and that must be assumed to have migrated over the 

 North Sea, were able to come over in the course of the last 

 7.000 vears. It must not be forgotten that according to J. A. 



Palmen (76) there are two lines followed by birds of passage 

 between England and the west of Norway ; and that there may 

 also have been other chance means of transport. 



All things considered, I am inclined to believe that in trying 

 to explain the distribution of vegetable species and the paths 

 they have followed, we shall arrive at better results by study- 

 in e- the wavs in which thev spread at the present time than 



