Page:Polar Exploration - Bruce - 1911.djvu/94

90 and are far more numerous in the Arctic than in the Antarctic Regions. For whereas there are about 400 species of flowering plants in the Arctic Regions, until Dr. Charcot discovered two flowering plants in more than one locality on the western coast of Graham Land—a grass, Aira antarctica, and a small umbelliferous plant, Colobanthus crassifolius var. brevifolius—no flowering plant was known to exist in the Antarctic Regions with the exception of this grass, which was known to be a native of the South Shetlands. A considerable number of plants, however, occur on some subantarctic islands, such as Kerguelen, South Georgia, etc. Except these two flowering plants which I have mentioned not a single one has yet been found on any land in the vicinity of Antarctica or the islands immediately adjacent to that continent, not even in the South Orkneys. Though grass had been reported on these islands, we know now that it certainly does not exist.

The most likely reason for this absence of flowering plants is the short Antarctic summer with temperatures very much below those of the Arctic Regions. In the South Orkneys, for instance, in 60° 44′ S. the mean summer temperature of the three summer months (December, January, and February) is below freezing-point, viz. 31.7° F.; and in no month does the mean rise to 33° F.; at Snow Hill,