June 1905.] BOTANICAL SOCIETY OF EDINBURGH. 109 
Asia and Europe. A number of small plants were found 
between some podetia of Placodiwm fruticulosum. Rocks in 
Scotia Bay, South Orkneys. 
Some fragments of crustaceous lichen are amongst the 
material brought from the South Orkneys, which, however, it 
is impossible to identify at present. 
But disregarding these we have betore us, brought back 
by the Scottish National Antarctic Expedition, eleven species 
from the South Orkneys. It is difficult with these few 
specimens to draw any conclusions, but it is interesting to 
note that all are found in the Arctic regions, and five are 
more or less Alpine. The new species is, of course, not 
included in these observations. 
In a paper on the Greenland Lichens collected by 
Vanhoffen (‘ Bibl. Bot.,” No. 42, 1897), the author of the 
present paper mentions that of the 286 known Greenland 
species, 213 were found alsoin Germany. Of these latter 105 
(i.e. 49°4 per cent.) are purely Alpine species, 11 (51 per cent.) 
prefer Alpine conditions, and 97 (45:5 per cent.) are equally 
at home on the hills and in the plains. That is to say, 54°5 
per cent. are typical hill-species, and none of the Greenland 
lichens found in Germany are confined to the lowlands. The 
lichen-vegetation of the former very closely corresponds, 
therefore, to the German Alpine flora. 
We have not enough material to make such a complete 
comparison of the Antarctic lichens, but I would like to give 
some statistics attempted with the lichens brought back by 
H.M. Discovery ships “ Erebus” and “Terror” in the years 
1839-1843. These number about 124, and 44 are apparently 
extra-European. But of the remaining 80 species, which 
also occur in Europe, 2°5 per cent. are typical lowland plants, 
23°75 per cent. typical Alpine plants, 66°25 per cent. are 
found on hillside and in lowland equally, 7-5 per cent. are 
exclusively Arctic, but of all the Antarctic and European 
species 73°75 per cent. occur also in the Arctic regions. 
Even the small material before us therefore admits of some 
interesting reflections on the great similarity between the 
Arctic, Alpine, and Antarctic regions in their lichen 
vegetation. 
We can imagine the ancient polar floras having been 
continuous at one period, and then, with the decrease in 
