CONDITIONS AFFECTING DISTKIBUTtOtf. 59 



other like hard rocks, which constitute the principal mass 

 of the ground present, like the clay, a vegetation somewhat 

 uniform, essentially composed of a small number of species 

 combined and diffused in immense masses. 



' But it is not the same in the plain, where the earth is 

 more friable. In the high mountainous lands there are 

 often met with great and small oases of friable schists 

 which often present the appearance of flower gardens in 

 the midst of rocky deserts covered with mosses and heaths. 

 It is there that the Arctic flora has its principal domain. 

 Resembling greatly that of Greenland and Spitzbergen, 

 it is specially characterised by species of plants diffused 

 in great quantities, such as the Dryas octopetal, L. ; the 

 tialix reticulala, L.; the Carex rupestris, AIL; the Thalictrum 

 alpinum, L., &c. This schistose flora has everywhere a 

 character pretty easily recognised. It does not stand mild 

 winters. There, where the mountains are too near the sea, 

 the schist is poor in species, and these Arctic oases of 

 flowers are met with, and found to abound, in those regions 

 in which the highest mountains, and the most extensive 

 neVes of snow, protect them against the hurtful sea air 

 brought by the west winds. 



' It is thus that a colony of Arctic plants shows itself to 

 the east of Folgefoun, in Hardanger. In Lem, in Bage, 

 and on the Dovrefjeld, and in its mountains, there is found a 

 rich Arctic flora protected against the influence of the sea 

 by the ne've'or snowfield, and by the Joetunfjelde. In the 

 north it is only in Salten and in Swedish Lapland that a 

 characteristic Arctic flora is to the same degree protected 

 against the sea winds by the high mountainous regions, 

 and the great neves of Sulitelma. In Finmark, in fine, is 

 found a rich Arctic flora to the east of the high mountains 

 and the great neV^s of the peninsula of Lyngen. 



'Very different from this is the Boreal Flora, which 

 equally shrinks from the climate of the coast, although it 

 is found to the west and to the east of the mountain 

 ridges. It is on the great masses of stones at the base of 

 precipitous mountain walls that it is met with in the 



