

[Vol. 2 



94 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



coast flora,' ' while among other species belonging to Blytt's 

 group Rhynchospora alba, Alnus glutinosa, Myrica Gale, 

 Arnica montana, Erica Tetralix, Ranunculus Flammula, Ly- 

 chnis Flos-cuculi, etc., may be mentioned, which grow on the 

 low-lying land in many parts of southern Norway. As a rule, 

 they prefer, it is true, damp places, but some species go right 

 up to the Birch Zone on the mountains, so they may be pre- 

 sumed to have immigrated from the southeast through 

 Sweden; but there is nothing to prove that this took place 

 just at the maximum of the Littorina Subsidence. As in- 

 stances, indeed, of the contrary, Alnus glutinosa from the 

 Birch Period and Myrica Gale from the Oak Period are found 

 in Norwegian peat-bogs and were, therefore, much earlier. 



I believe that the west European coast flora on the west 

 coast of Norway immigrated directly, by fits and starts, from 

 England; but we will return to this later on. 



THE PICE A EXCELSA TERIOD 



According to archaeological calculations, the Scandinavian 

 Stone Age lasted about 3,000 years, so that the Bronze Age 

 in Scandinavia began about 4,000 years ago. During this 

 period the climate was undoubtedly warmer than it now is, 

 and it was not until the Bronze Age that any noticeable fall 

 seems to have taken place. 



At the beginning of the Stone Age the land around Kristi- 

 ania lay 230 feet lower than at present, but during the Stone 

 Age it was elevated about 184 feet, and during the Bronze 

 Age it rose to about its present height above sea-level. 



In the Bronze Age, or perhaps in the latter part of the 

 Stone Age, Picea excelsa migrated into Norway from the 

 east, from Finland through Sweden. In Finland it is si ill 

 found as a fossil in the Oak Period, and in Sweden, especially 

 in the north and east, it is so found, while spruce is not found 

 fossilized in the south of Sweden or Denmark after the Glacial 



Epoch. 



In the north of Norway (Fimnark) there are occurrences 



of spruce that are entirely independent of the spruce's great 



province of distribution in the south of Norway. It appears 



