Page:The Botany of the Antarctic Voyage.djvu/245

Falklands, etc.] strait of Magalhaens to be the northern limit of the Fuegian Flora eastward of Port Famine, and have included in, or rather added to that Flora, all the known plants of the Pacific side of the Andes, reaching north to the Chonos Archipelago. The latter position is peculiar, in the Beech being there replaced, at the level of the sea, with other trees; by the sudden change in the aspect of the coast vegetation that the flora of Chilöe, immediately to the northward, presents; and by its being only a few miles beyond the "glacier-bound Gulf of Peñas," where perennial ice descends to the level of the ocean in a latitude nearly midway between the Equator and the Antarctic Pole.

The successive labours of Commerson, Banks and Solander, and of Menzies, early called the attention of Botanists to the singular aspect of the Fuegian Flora, apparently incompatible in its luxuriance with the rigour of the climate. The subsequent exertions of Captain King and Mr. Anderson, and of Darwin, dining the voyages of Captain Fitzroy, of D'Urville, and the officers of our own late Antarctic Expedition, have nearly exhausted the Phænogamic productions. Much remains, however, to be done amongst the lower Orders, for the last-named expedition procured from a small island in the immediate vicinity of Cape Horn, more than twice as many Cryptogamic species as had been previously detected in the whole of Tierra del Fuego. These, however, hardly affect the general aspect of the vegetation, which may now be considered as satisfactorily known.

The Falkland Islands rank next in botanical importance to Fuegia. Though lying to the northward of the main body of that country, their vegetation is so influenced by climate and by some other peculiarities common to these islands and the Patagonian plains, that they produce no tree whatever. They are situated between the parallels of 51° and 53°, and the meridians of 57½° and 61½° west, and consist of an eastern and western island, nearly equal in size, and together forming an oval, whose axis lies east and west and extends about 160 miles. The general outline is jagged, like that of Fuegia, and similarly indented by deep inlets and ramifying bays but their level or undulating surface, never rising above 2000 feet, and the geological formation, bear no resemblance to an archipelago formed by a submerged chain of mountains. Altogether, the Botanical and other characters of the Falklands are allied to the Atlantic coast of Patagonia, opposite to the strait of Magalhaens, from whence they are only 300 miles distant.

The most evident causes for the absence of trees in the Falkland Islands are the dislocation or removal of that group from the main land; their comparatively plane surface, everywhere exposed to the violence of the westerly gales, and more especially to the rapid evaporation and sudden changes in temperature and in other meteorological phenomena. The southerly and westerly winds are violent, cold, and often accompanied by heavy snow-storms; the easterly and northerly arrive saturated with warmer sea vapours, which, quickly condensing over the already chilled surface of the sod, form fogs and mists that intercept the sun's rays; whilst the north-westerly winds are singularly dry and parching, from the influence of the Patagonian plains over which they blow. Such sudden alternations from heat to cold, and