Bis 
Bd. IV: ıı) THE LICHENS. 65 
seasons. The mere collection of material is no longer all that we require. In what 
condition are the lichens during the long winter? At what temperature does assi- 
milation commence? It is not of real use to try experiments on plants in warmer 
climes. Because we want to see how these small plants can live under these most ad- 
verse conditions prevailing in the antarctic regions. Every where we find lichens on 
the outer limits of vegetation. The power to become quite dry and yet not die is 
their chief ecological distribution factor. We must believe that it is this property 
which enables them to spread slowly but surely into the most inhospitable regions. 
Unconsciously they are making their way towards the south pole but so far they 
can have been beaten in this race only by the perpetual covering of snow. I have 
not the slightest doubt that if bare rocks are found in the neighbourhood of the 
South Pole that we will find Lichens growing there. 
The following table will show as has been shown before what a small difference 
there is between the arctic and antarctic lichen floras. I have compared the lichens 
found in Subantaretic America, South Georgia and the Antarctis with those met 
with ‘in the Arctic district which includes Arctic America, Greenland, Spitsbergen 
and Iceland (DARBISH. Fram): In the list I have shown the absolute numbers and 
the percentages of those species of the three distriets just mentioned which occur 
in the Arctic district referred to: 
Frutic. Foliac. Crust. Totals. 
Subantarctic America . . . . 30 or 80 % 19 or 19 % 41 or 21 % 90 or 24 % 
South Georpga. „2.2... IT >» 80 >» 3,3 25 3 I5 > 50 > 297 35312 
EITREALCEISTEENE ee 10, 3 15205 9» 50» 27 > 40 > 46 > 43 > 
Practically half the antarctic plants then are common also to the Arctic. 
These figures also show that the similarity of subantarctic to arctic plants as far as 
lichens are concerned is less striking than that of antarctic to arctic. Wainio has al- 
ready made comparisons of this kind with regard to the lichens brought back from 
the Straits of Gerlache by the “Belgica”. Of the 55 species found in this region 21 
or 38.18 % are known from arctic or temperate Europe, 9 species or 16.36 % are also 
to be found in subantarctic America and 29 or 52.73 % were knew to Science. 
(Waın. Belg. p. 3.) 
This point is again referred to by SCHENK (SCHENK Kerg. p. 176). But from 
the above statistical notes the relations of arctic to antarctic lichen flora become still 
more striking. 43 % of the antarctic lichens are found in the true arctic (and not 
temperate regions), 53 % of the South Georgian lichens and only 24 % of the sub- 
antarctic American species. 
9-—-112865. Schwedische Südpolar- Expedition 19017—1903. 
