Page:Aspects of nature in different lands and different climates; with scientific elucidations (IA b29329668 0002).pdf/197

 *[Footnote: This experienced traveller, who had been placed by Ferdinand the Catholic as director of the gold-washings in Hayti, says: "Among the many ferns there are some which I reckon among trees, for they are as thick and as tall as pines (Helechos que yo cuento por arboles, tan gruesos como grandes pinos y muy altos). They grow chiefly in the mountains and where there is much water." The height is exaggerated. In the dense forests round Caripe even our Cyathea speciosa only attains a height of 30 to 35 (32 to 37 English) feet; and an excellent observer, Ernst Dieffenbach, in the northernmost of the three islands of New Zealand saw no stems of Cyathea dealbata of more than 40 (42-1/2 English) feet in height. In the Cyathea speciosa and the Meniscium of the Chaymas missions we observed, in the midst of the shadiest primeval forest, in very luxuriantly growing individuals, the scaly stems covered with a shining carbonaceous powder. It seemed like a singular decomposition of the fibrous parts of the old frond stalks. (Humboldt, Rel. hist. T. i. p. 437.)

Between the tropics, where, on the declivities of the Cordilleras, climates are placed successively in stages one above another, the proper zone of the tree-ferns is between three and five thousand feet (about 3200 and 5330 English) above the level of the sea. In South America and in the Mexican highlands they seldom descend lower towards the plains than 1200 (about 1280 Eng.) feet. The mean temperature of this happy zone falls between 17° and 14°.5 Reaumur (70°.2 and 64°.6 Fahr.) This region enters the lowest stratum of clouds, or that which floats next above the]*