Page:Polar Exploration - Bruce - 1911.djvu/99

Rh as well, but the majority of these are of more or less cosmopolitan distribution. Only six Antarctic hepatics are known, and only one fungus discovered by M. Racovitza of the Belgica.

Lichens predominate though more numerous as individuals than species. Various orange-coloured species of Placodium even show well-marked coloration on precipitous rocks in winter. The grey and shaggy Usnea melaxantha, Ach., is more luxuriant than any other and produces good "fruits." All but one of the South Orkney lichens collected by Dr. Rudmose Brown of the Scotia have been previously recorded from the Arctic Regions. Altogether about 75 per cent. of the Antarctic species are also Arctic forms. Twenty-five species of marine algæ, including five new species, were taken by the Scottish Expedition in South Orkney waters. Of diatoms I have already spoken. Fresh-water algæ are almost confined to unicellular kinds, but had been little studied until Mr. James Murray found "abundance of fresh-water algæ, including some very small diatoms, in ponds, and also in earthy deposits, which may have originated in ponds."

This is a brief summary of all that is known regarding the Antarctic flora. It is quite impossible to enter into similar detail regarding the Arctic flora on account not only of its profusion, as already indicated by the number of