Page:The Botany of the Antarctic Voyage.djvu/382

346 friend Mr. Darwin, it is advisable to sum up the principal facts connected with their history, adding some little from personal observation. These remarks will be the more appropriately introduced here, from the two principal species having been first imported into England by the Antarctic Expedition, and now promising to become useful and ornamental additions to our forests; as, also, from their geographical range having been used as an indication of the limits of the Antarctic Flora.

The Fagus Antarctica has always been recognized as a true Beech, from the very marked resemblance its deciduous foliage bears to that of the European F. sylcatica. The other common Fuegian species, F. betuloides, with coriaceous leaves of a deep green hue very similar to those of the Scottish Birch, was, up to the discoveiy of its flowers, considered to be a Betula. The habit of both species, however, is essentially that of the Beech, and so are the form of trunk, smooth bark, and especially the spreading ramification and horizontal divaricating ramuli; whilst their flowers and fruit resemble so closely in all but size, those of the European Fagus sylcatica, that I consider them as undoubted congeners of that plant.

I have elsewhere (vid. ante p. 277) alluded to the very common error of holding the locality in which a certain species particularly abounds, to be the principal habitat of the order or genus to which it belongs; this often arises from attaching a greater importance to the spread of the species than that of the genus. Naturalists unacquainted with the range of the Beeches, will be surprised to hear that they are more characteristic of the temperate and cold latitudes of the southern, than of the northern hemisphere, even in the proportion of five to one. Thus, one species alone is European, and one American; two are found on the mountains of Java; one is characteristic of the Alps of Tasmania, where the only Antarctic representatives of the Australian Flora are found; four inhabit the high mountains of the northern or lower levels in the middle and southern Islands of New Zealand; and, lastly, as many as seven have been described from Chili and Fuegia.

Of the seven so called Chilian and Fuegian species, three are well marked, and afford instructive examples of the succession of species in proceeding northward from Cape Horn; they are the F. Antarctica, betuloides, and obliqua; the others, which may be varieties of the above, though from the want of copious suites of good specimens I advance this opinion with much hesitation, are F. Pumilio, Poepp. and Endl., F. procera, P. and E., F. Dornbeyi, Mirb., and F. alpina, P. and E.

The Fagus Antarctica, justly so named, ascends even at Cape Horn much higher than F. betuloides, and nearly to the summits of the mountains, which are perhaps 1000 feet below the assumed level of perpetual snow in that latitude, while at the sea it forms much the larger tree of the two. supposing the continent of America to have been produced indefinitely to the southward, in a free ocean, the F. Antarctica would be found extending to as high a parallel as 62&deg; S., whilst the F. betuloides would cease at the 60th degree: assuming that both species followed the same ratio of ascent that very many other Cordillera plants do, which ascend from the level of the sea in Fuegia to a considerable elevation in a lower latitude.

Fagus betuloides, though by far the most prevalent species in Hermite Island, and, indeed, throughout Fuegia, has its principal parallel about the Strait of Magalhaens, where it becomes a very large tree. It forms the prevailing feature in the scenery of Tierra del Fuego, especially in winter time, from having persistent, evergreen leaves, and from its upper limit being sharply defined and contrasting with the dazzling snow that covers the matted but naked branches of the F. Antarctica, which immediately succeeds it. Its upper limit at Cape Horn (lat. 56&deg;) is about 800 feet; in the northern parts of Tierra del Fuego it reaches 1,400 feet; and, if the F. alpina, P. and E., be a state of the same species in its most northern locality, its level in lat. 36° is between 5,000 and 8,000 feet.

The following notice of the dimension the Evergreen Beech attains in the Strait of Magalhaens, is extracted from Capt. King's excellent 'Voyage of the Adventure and Beagle' (p. 576). "At Port Famine and in the