STEJ NEGER] ANIMALS AND PLANTS OF NORWAY 489 
Beginning with the plants, we have two extreme parties among 
the phytogeographers, those who insist upon the slow and gradual 
dispersal of the flora over land connections, and those who, like 
Warming and Sernander, see no difficulty in assuming that entire 
plant associations by the aid of wind, ocean currents, migrating birds, 
etc., are enabled to cross extensive bodies of salt water, such as the 
Skagerak, the North Sea, or even greater stretches of open ocean. 
These diametrically opposed views have led to a very instructive 
discussion about the dispersal of the flora of the FerdGes,. which it 
will be profitable to review here in some detail, because of the 
direct bearing it has upon our own studies. 
In the “ Botany of the Fzerdes based upon Danish Investigations,” 
pt. I, pp. 112-119 (Copenhagen and London, 1901), C. H. Osten- 
feld has a chapter on “ The Immigration of the Flora,” in which he 
states as his belief derived from a study of the phanerogams and 
pteridophytes and a full discussion of the various theories, that apart 
from a few species “introduced by the agency of the winds (and 
birds?),” “the chief part of the present flora of the Fzr6des has mi- 
grated across a postglacial belt of land” (p. 118) from Scotland, 
with the flora of which it “bears a wonderful resemblance.” He 
thinks that “if it had been a question of immigration across the 
sea, the flora taken as a whole would hardly have been so very 
much like that of Scotland. It would have consisted of fewer 
species”’ (p. 115). The above conclusions were based upon the 
vascular plants, with the exception of the difficult group of the 
Hieracia which were studied by H. Dahlstedt. From the latter’s 
account (Bot. Feeroes, pt. 11, 1903, pp. 625-659) I quote the fol- 
lowing: 
“Usually the different forms have not a wide geographical dis- 
tribution. I am therefore of opinion that the study of the Hieracia 
of a single district in its relation to the neighbouring floral districts 
ought to be particularly useful as a contribution towards the solving 
of various plant-geographical questions. This has become still more 
clear to me by studying the Hieracium-flora of Scandinavia. I 
think that it will more particularly be of great help to us in deter- 
mining the ways by which a flora of a land immigrates, and also 
the relative time for its immigration. The composition of the 
Hieracium-flora of the Ferdes confirms the opinion expressed by 
C. H. Ostenfeld regarding the origin of the rest of the phanero- 
gamous flora” (p. 626). 
“Tt is an interesting fact that the Atlantic element in this genus 
