666 



possible to conclude from the absence of endemic species in an insular 

 flora that it must necessarily have immigrated a cros s land, and 

 later on Nathorst also appears to have changed his opinion on this 

 point, at least in his later writings he expresses himself more doubt- 

 fully as regards the England-Greenland connection and thinks that 

 even if a post-glacial land -bridge had existed it was at any rate, 

 not of so great an importance for the immigration of the flora as 

 he had previously believed. He even mentions the existence of the 

 postglacial land connection as »etwas zweifelhaft 1 .« 



Among the botanists, who have maintained the theory of an im- 

 migration across a glacial or post-glacial land-bridge, mav be men- 

 tioned O. Drude 2 and Ostenfeld (see p. 113 above). A. Blytt has, 

 on the other hånd, advocated the possibility of a pre-glacial or glacial 

 land connection only, but not of a post-glacial one as assumed by 

 Ostenfeld (p. 113 above), and which I also had believed previously 4 . 



We see from the above that geologists had previously, very 

 little to say in defence of a post-glacial land connection, and lately, 

 they appear to be quite sceptical as regards the theory in question. 



On his map of »The Great Ice-sheet« (Om Skandinaviens geo- 

 grafiska utveckling efter Istiden, Stockholm, 1896) De Geer has 

 marked out the Færoes covered by an ice-sheet which extends 

 somewhat beyond the land, and otherwise surrounded on every 

 side by floating icebergs, exactly as in Geikie's Plate D. (»Map of 

 Europe showing extent of the glaciated areas at the climax of the 

 Ice Age«) where, according to the investigations made by Helland 

 and Geikie, the Færoes are shown with their local ice-sheet 

 flowing outwards in all directions and separated by the sea from 

 the great continuous ice-sheet of northern Europe, the edge of which, 

 lies to the west of the Shetland Islands. He says distinctly (p. 45) 

 that during a part of the glacial period a land-bridge is supposed to 

 have existed, but as yet nothing is known for certain as regards 



1 Nathorst: Kritiska anmårkningar om den grdnlåndska vegetationens hi- 

 storia (Bihang t. K. Sv. Akad. Handlingar. Bd. 1(5, 1890, p. :57 and pp. 4'J -43); Id.: 

 Fortsatta anmårkningar om den grdnlåndska vegetationens historia (K. Vet. Akad. 

 Ofversigt, 1891, p. 232). Id. in Englers Jahrb., XIV, 1891, pp. 209— 14. 



2 »Pfanzengeographische Anhaltspunkte fur das Hestehen einer Landbrucke 

 zvvischen G ro n land und West Europa zur Kiszeit« in Das Ausland, 1883. 



8 Englers Jahrb., vol. II, p. 49 and p. 177. 



4 Warming: »Grenlands Natur og Historie . Videnskabelige Meddelelser Ira 

 Naturhist. Forening, 1890, p. 290, and Kuglers .lalirlnieher, XIV, p. 481. 



