809 



at the end of the Pliocene period, that the sea-level was 80 — ^100 meters 

 above the present high water-mark and that the contours of the coast 

 were ahnost the same as now. At the close of the glacial period, when 

 almost the whole country was covered by inland ice, the level of the 

 sea was at the coast 80 — 130 meters above the present high water- 

 mark and gradually sank down to 30 — 40 meters, when the animal 

 life at the coast had become the same as it is now. Raised beaches 

 are to be seen all round the coast in every inlet. It seems to me 

 for these reasons, that Iceland cannot possibly have been connected 

 with other countries during a postglacial period.« 



With regard to the immigration of the flora on the whole, re- 

 ference may be made toWarming's above-mentioned, detailed work, 

 and I shall now pass on to discuss the possibilities of immigration 

 as regards the algæ, especially the marine algæ. The latter, which 

 live in the sea, are of course widely different from the land flora, 

 so far as the present question is concerned. In my paper on the 

 fresh-water algæ of the Færoes (7) I have pointed out, as already 

 mentioned, that the supposition is at least tenable, that the fresh- 

 water algæ have been transported to the islands by hirds or the 

 wind. As to several marine algæ, especially littoral algæ, it also 

 seems to me most probable, that birds have contributed to their 

 distribution. It is now said, however, that migratory birds not only 

 journey with stomachs empty but are on the whole clean (comp. 

 Ostenfeld p. 116); yet small crusts of mud and similar substances 

 have frequently been found on the beaks and feet of the birds. 

 Spores and resting cells can very well be hidden in these crusts 

 (comp. Winge's observations in Warming's paper (83, p. 676)). 



The birds which might be supposed to carry the algæ, for in- 

 stance, from Shetland to the Færoes need not, however, be migratory 

 birds only. The distance between these two groups of islands is only 

 about 300 kilometres, and numerous birds journey everywhere across 

 the sea between them. When fogs and tempests suddenly arise, the 

 birds may very easily be blown off from one coast to another, and it is 

 even very probable, that some of the many sea birds, perhaps parti- 

 cularly the wading birds which live on the coasts of Shelland and the 

 Færoes sometimes visit the one coast, sometimes the other. Even 

 halfway between the islands large flocks of gulls, fulmars and gan- 

 nets may be met with, and it cannot be supposed that these birds 

 always return to the same coast. 



In order to have an opinion from a competent authority on 



