280 O. GJ/EREVOLL 



when drawing parallels with the present situation in Greenland, but it is by 

 no means an impossible hypothesis to postulate an inland nunatak refugium 

 in the Gjevilvasskammene Mts. The steep south-facing slopes might have 

 offered sufficiently favorable living conditions for a hardy flora. If this 

 theory be correct, it gives us a much more likely explanation of the distribu- 

 tion and migration of many species than does a theory confining the plants to 

 a coastal survival area only. 



It should be added that the geologist H. Reusch proposed as early as 

 1884 that mountain areas in the central and western parts of southern Norway 

 must have protruded from the ice sheet as nunataks. Recently Dahl (1961) has 

 drawn attention to the "felsenmeers" (= mountain top detritus) of the 

 mountain tops. He is of the opinion that on the basis of the degree of disinte- 

 gration, the lower "felsenmeer" border corresponds to the surface of the in- 

 land ice. If this hypothesis proves correct, many and large nunatak areas 

 have existed in southern Norway during the Ice Age. 



Concerning the possibiUties of higher plants persisting in a nunatak area, 

 several geologists have expressed doubt that the climatic conditions would 

 permit any kind of plant life. Observations from Greenland nunataks confirm 

 that higher plants are able to persist there. Furthermore we know of a fairly 

 rich flora from the tundra district of Peary Land. Holmen (1957) reported 

 96 phanerogams from this area. According to Koch (1928), the mean annual 

 temperature is 20°C below zero. For about 100 days the temperature hovers 

 around — 40°C. The precipitation is mainly in the form of snow, and amounts 

 to less than 100 mm. In this connection it is important to state that the sum- 

 mer temperature rises only to some few degrees above freezing (0°C); in 

 July it has an average of ca. 6°C. 



In North America it is now generally accepted that plants as well as 

 animals found a refugium in the Canadian Arctic Archipelago. It would be 

 very unlikely that more severe conditions existed on coastal mountain 

 refugia in Norway than in the tundra refugia of Arctic Canada. 



I have mentioned some of the detailed taxonomical investigations per- 

 formed by Nordhagen (1931, 1935, 1952) and Nannfeldt (1940) and their 

 great significance for the survival theory. In this connection I also want to 

 recapitulate the recent cytological studies of Papaver radicatum performed by 

 Dr. Gunvor Knaben (1959). During a number of years she crossed poppies in 

 order to investigate variation within the Papaver radicatum complex. The 

 evolution within many genera most certainly corresponds to structural 

 chromosomal alterations. If the parent plants have the same chromosome 

 number but a different chromosome structure the result of the cross gives an 

 irregular meiosis. 



Dr. Knaben crossed poppies from a number of localities in southern 

 Norway and she reached the following conclusion: in southern Norway there 

 are six different races of Papaver radicatum. They all have a ditTerenl 



