president's address. 
127 
tinuous ice, and the effect of this ice-sheet is thus stated with the 
enormous weight in its favour (in part) of Sir J. D. Hookers 
approval.* “ Even if Iceland were not entirely buried under an icy 
covering, yet the climatic conditions of the last glacial epoch must 
have sufficed to destroy such a flora as it now possesses. And the 
same must have been the case with Greenland. Indeed, I do not 
see how it is possible to resist the conclusion that the floras of all 
these high latitudes must have been introduced since the close of 
the Glacial Epoch. And as the plants could only have migrated 
over a land surface, we are compelled to infer that in post-glacial 
times the Fmroo Islands, Iceland and Greenland, and Spitsbergen 
also, must have been united to the European Continent.” 
The passage quoted clearly states two things (which I have 
italicised), viz., that an ice-sheet destroys the flora, and that a land 
surface is necessary for the immigration of plants. Surely we are 
justified in reasoning from existing circumstances which we can 
study, rather than in relying on hypotheses of which we can have 
no proof. 
There are three conditions of cold and hardship which we may 
suppose to be very detrimental to the flora of any country : — 
An ice-sheet. 
Extensive glaciation by glaciers. 
Intense cold, with comparatively little shelter for plants. 
Let us inquire how these conditions affect floras in Arctic regions 
at the present time. 
First — Ice-sheet. Greenland is now covered by an ice-sheet, 
how thick in the centre of that country no one knows, probably 
some thousands of feet ; but even in such severe glaciation as this, 
there is in many places a margin left uncovered near the sea, and 
there are also rocks — “ Aunataks — ” protruding through the ice, and 
in these situations a not inconsiderable flora holds its own. 
Professor Warming, of Copenhagen, having visited Greenland, 
has gone in great detail into the question of Arctic distribution. 
Publishing in 1888+ tables in which he traces the flora known 
* ‘ Prehistoric Europe ’ (1881) p. 519. 
+ * Tabellarisk Oversigt over Gronlands, Islands, og Fivroernes Flora ’ 
(Kjobenhaven, 1888). 
