

[VOL. 



82 ANNALS OK THE MISSOURI BOTANICAL GARDEiN 



of Norway, but on the coast of Spitzbergen, and indicates a 

 mean temperature of from — 3 to — 7°C. and thus quite 

 an arctic climate. At Kristianssand these arctic plant- 

 remains are found together with remains both of Yoldia 

 arctica and Mytilus edulis, while Salix polaris, near Kristi- 

 ania, is found with Mytilus and far below the highest marine 

 boundary. 



Two questions now present themselves, ( 1 ) did Salix polaris 

 and other arctic vegetation continue to live during the Last 

 Glacial Period upon a stretch of coast in the west and north 

 of Norway that was not covered with ice, or (2) did Salix 

 polaris and the other arctic plants immigrate from Jutland 

 — where they lived < luring the Last Glacial Period — to the first 

 land from which the ice disappeared at Kristianssand, and 

 thence spread along the edge of the ice on both sides as the 

 latter disappeared? 



I have previously endeavored to uphold the first of these 

 views as the more probable, having found ('05, p. 337) that 

 the discoveries hitherto made of the remains of arctic plants 

 favored the belief that ' during the Last Glacial Period there 

 lived in Norway a high-arctic vegetation upon a strip of coast 

 that was free from ice and must have extended about as far 

 down as the Sogne Fjord. Subsequently, as time went on, 

 several species of high-arctic plants that had immigrated from 

 Russia and Siberia made their way for a greater or smaller 

 distance southward in the north of Scandinavia.' 



Various later discoveries of arctic plants all the way down 

 to the south point of Norway go to prove that the iceless 

 margin of coast may have extended thus far, at any rate par- 

 tially. The isolated occurrence of Saxifraga A'izoon, growing 

 upon the mountains in inner Ryfylke, east of Stavangor, is 

 also difficult to understand unless it is assumed that it mi- 

 grated thither from an iceless margin of coast, as this species, 

 beyond being found in the Alps, is only known in Nordland 

 in Norway, and in Iceland and Greenland. 



But it seems probable that here a number of vegetable 

 species from the interglacial period may have survived the 

 Last Glacial Period. This must have been the case with 



