Remarks about the Relations 
of the Floras of the Northern Atlantic, the Polar Sea, 
and the Northern Pacific. 
By 
Herman G. Simmons. 
Lund, Sweden. 
It is a fact, known already for a long time, that a great 
many species of tlie northern hemisphere have a cireumpolar 
distribution. An Interpretation of tliis circumstance became 
possible first when geologists had come to know the Gflacial 
Period and its effects. After similar views had been advanced 
in the works of Forbes, Lyell and others, Darwin in 
Origin of species (12) shows how the iceage must have driven 
the old tertiary plants of the districts around the pole, or their 
descendants, from the territories they once occupied, southwards 
into the continents of our time, where they found an asylum during 
the glaciation. At the time when the ice again melted away 
they began slowly to wander back, interspersed with alpine 
elements from the districts where they had survived the iceage. 
At the same time they also left tribes in their temporary 
homesteads, whicli contributed to a new colonization of the 
Southern mountains. In such a manner the great number of 
cireumpolar species is accounted for and likewise that contingent 
of species, which every arctic district has in common with the 
alpine region of the mountains south of it, but not with other 
districts. 
This theory, further developed by Sir Joseph Hooker in 
his Outlines of distribution of arctic plants (24) and by later 
authors, is now universally adopted and doubtless well founded. 
Still it has as yet mostly been brought to bear only upon tlie 
higher plants, or at most upon tlie landvegetation as a whole. 
As far as marine algae are concerned only few writers have 
tried to make use of this point of view for the explication of 
the present distribution of species and genera. However, some 
suggestions are made by Kj eil man (30) and Reinke (40). 
