- [Footnote: sea and the plains; and hence, besides great equality of temperature,
it also enjoys uninterruptedly a high degree of humidity. (Robert Brown, in Appendix to Expedition to Congo, p. 423.) The inhabitants, who are of Spanish descent, call this zone "tierra templada de los helechos." The Arabic word for fern is feledschun, f being changed into h in helechos according to Spanish custom: perhaps the Arabic feledschun is connected with "faladscha," "it divides;" in allusion to the finely divided margins of fern leaves or fronds. (Abu Zacaria Ebn el Awam, Libro de Agricultura, traducido por J. A. Banqueri, T. ii. Madr. 1802, p. 736.)
The conditions of mild temperature and an atmosphere nearly saturated with vapour, together with great equability of climate in respect to both temperature and moisture, are fulfilled on the declivities of the mountains, in the valleys of the Andes, and above all in the mild and humid atmosphere of the southern hemisphere, where arborescent ferns extend not only to New Zealand and Van Diemen Island (Tasmania), but even to the Straits of Magellan and to Campbell Islands, or to a latitude almost corresponding to that of Berlin in the northern hemisphere. Of tree-ferns, Dicksonia squarrosa grows vigorously in 46° South latitude, in Dusky Bay (New Zealand); D. antarctica of Labillardière in Tasmania; a Thyrsopteris in Juan Fernandez; an undescribed Dicksonia with stems from 12 to 15 (nearly 13 to 16 English) feet in the south of Chili, not far from Valdivia; and a Lomaria of rather less height in the Straits of Magellan. Campbell Island is still nearer to the south pole, in 52-1/2° lat., and even there the stem of the Aspidium venustum rises to]*
