Page:The Botany of the Antarctic Voyage.djvu/248

216 gather from the account of Mr. Webster, the surgeon to that ship, that "no ph&aelig;nogamic plants, only a few lichens and sea-weeds," inhabit that dreary islet, although the temperature of its soil is raised by subterranean heat; its latitude is 63&frac12;&deg; south, and longitude 60&deg; west.

In January 1843 I landed upon a small islet, close to the main portion of Palmer's Land, in latitude 64&deg; 12' south, and longitude 57&deg; west. It appeared to be the "ultima Thule" of southern vegetation; the soil hard frozen, except on the very surface where it was thawed by a sun-heat which raised the temperature to 46&deg;, while the sea was encumbered with pack-ice and bergs; no flowering plants were to be seen, and only eighteen belonging to the Orders Lichenes, Musci, and Alg&aelig;. Beyond this latitude I believe there is no terrestrial vegetation.

The South Georgian group is situated about 1000 miles due east of Cape Horn, and exhibits a wholly different aspect from that land, being covered with perennial snows, and the harbours blocked up with everlasting glaciers; still, Captain Cook found a scanty vegetation, consisting of "a coarse strong-bladed grass, growing in tufts, wild Burnet, and a plant like moss, which springs from the rocks;" (vide Cook's 2nd voyage). The flora of South Georgia is probably intermediate in luxuriance (if such term may be used), between the Falklands and the South Shetlands, the proximity of the Antarctic Ice being influenced by that of the large bodies of land, it approaches nearer to South Georgia than to Fuegia, and renders that climate unsuited to support even a moderate vegetation.

Sandwich Land, discovered by Captain Cook, lies further south than South Georgia, and, like Palmer's Land, is encroached upon by the perennial ice of the Atlantic Ocean. That illustrious navigator mentions two hills clear of snow, and apparently covered with a green turf, but this is all we know of then productions.

Proceeding westward from Antarctic America, the next island that requires notice, as exhibiting an Antarctic vegetation, is Tristan d'Acunha. Though only 1000 miles distant from the Cape of Good Hope, and 3000 from the Strait of Magalhaens, the Botany of this island is far more intimately allied to that of Fuegia than Africa. Captain Carmichael's list (Linn. Trans., vol. xii. p. 483), contains twenty-eight flowering plants (I exclude Sonchus oleraceus); only one species of Phylica, and one Pelargonium, amounting to one-fourteenth of the whole, are Cape forms; whilst seven others, or one-fourth of the flora, are either natives of Fuegia or typical of South American Botany, and the Ferns and Lycopodia exhibit a still stronger affinity. There are some points in which the vegetation of Tristan d'Acunha resembles that of St. Helena and Ascension. Though these islands are separated from one another by nearly thirty degrees of latitude, they lie within eight degrees of longitude, and all are the exposed summits of ancient volcanoes, such as the highest peaks of the Andes might present, if that mighty chain were partially submerged. The relation between the floras of Ascension and St. Helena is