192 
Simmons, Remarks about tlie Relations of tbe Floras etc. 
rina does not a.llow to think of preglacial causes for its present 
appearance. 
Indeed tRere Ras been a great contest about tbe assuming 
of a postglacial landbridge over tbe nortbern Atlantic, and it 
is likely to be continued for some time yet. Tbere bave been 
brougbt forward many arguments for and against tbe tbeory 
from geological as well as from botanical and zoological point 
of view. Qeologists at present niostly seem averse to it. but 
as far as I can judge, tbey bave not prodnced any conclusive 
evidence against tbe possibibty of tbe postglacial upbeaval of 
tbe tertiary landconnection, or at least considerable parts of it, 
wbicli would be enougb to form ways of immigration at least 
for tbe marine algae, probably also for tbe flora of tbe lands 
in question. Tboroddsen indeed bas lately (Ymer 1904, b. 4) 
tbougbt bt to give an advice to botanists to explain tbe immi¬ 
gration out from tbe present conditions, but as be lias given 
no convincing proof of tbe impossibilit.y of the landconnection 
and bas besides sliown himself to be totally ignorant about 
some of tbe most important botanical facts on wbicb tbe oppo- 
site opinion is based, I cannot see tbat be is justified in giving 
any sucb prescription. 
As it cannot be tbougbt of quoting all tbe many works 
wliere tbe question of tbe landbridge is treated, I will only refer 
to one rnore of tbe latest, tbat is ratlier well in aecord witb 
tbe view I bave adopted. It is tbe great memoir of Hansen 
about tbe batbymetrical features of tbe nortbern seas (35). Tbe 
result of tbe autbor, reaclied tbrougb comparison of a great 
many observations, regarding tbe sculpture of tbe bottom of 
tbe Atlantic and tbe Polar Sea, is tbat great oscillations of sea- 
level must be assumed in different geological pCriods, even so 
late as at least at tbe end of tbe iceage. How late an upbeaval 
bas taken place is not distinctly said, and to judge from part 
of a letter from tbe autbor, that Börgesen (10) bas publisbed, 
be seems not to assume an emergence of land so late as during 
tbe warm postglacial time. But I cannot see, tbat bis researcbes 
contend against sucb a supposition, especially wben viewed in 
connection witb tbe above mentioned Statements of Hatborst. 
If tbe oscillations bave been synclironical, we must assume, tbat 
about the same time wben Spitzbergen was connected witb 
nortbern Europe and Asia, also great parts of tbe old submarine 
ridge were above sealevel, and as tbis took place in tbe warm 
period of tbe postglacial time, tliere must then bave ruled tbe 
conditions reqmred for immigration of a, temperate flora north- 
ward. Moreover Hansen (35, p. 71, 75, 123—126) points out 
tbat tbe absence of a typical coast-platform at tbe Eaeroes and 
most part of tbe coast of Iceland indicates a recent submer- 
gence. Tbe loose basaltic rocks of tliose islands are very rnuch 
subject to be cut down by tbe waveaction and still caves do 
only appear at present sealevel, postglacial marine Sediments are 
absent above tlie present shoreline of tlie Eaeroes, wbicb also 
