CONDITIONS AFFECTING DISTRIBUTION, 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 
Sali reticulata, L.; the Carex rupestras, All.; 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 
névés 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 néyé 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 névés of Sulitelma. In Finmark, in fine, is 
found a rich Arctic flora to the east of the high mountains 
and the great névés 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 
