- [Footnote: *perate zone, in the Alps (lat. 45-3/4°), Pinus picea (Du Roi)
advances highest, leaving the birches behind; and in the Pyrenees (lat. 42-1/2°), Pinus uncinata (Ram.) and P. sylvestris var. rubra: within the tropics, in lat. 19°-20° in Mexico, Pinus Montezumæ leaves far behind Alnus toluccensis, Quercus spicata, and Q. crassipes; while in the snow mountains of Quito at the equator, Escallonia myrtilloides, Aralia avicennifolia, and Drymis winteri, take the lead. The last-named tree, which is identical with Drymis granatensis (Mut.) and Wintera aromatica (Murray), presents, as Joseph Hooker has shewn (Flora Antarctica, p. 229), the striking example of the uninterrupted extension of the same species of tree from the most southern part of Tierra del Fuego and Hermit Island, where it was discovered by Drake's Expedition in 1577, to the northern highlands of Mexico; or through a range of 86 degrees of latitude, or 5160 geographical miles. Where it is not birches (as in the far north), but needle trees (as in the Swiss Alps and the Pyrenees), which form the limit of arborescent vegetation on the highest mountains, we find above them, still nearer to the snowy summits which they gracefully enwreath with their bright garlands, in Europe and Western Asia, the Alp roses, the Rhododendra,—which are replaced on the Silla de Caracas and in the Peruvian Paramo de Saraguru by the purple flowers of another genus of Ericaceæ, the beautiful race of Befarias. In Lapland the needle-trees are immediately followed by Rhododendron laponicum; in the Swiss Alps by Rhododendron ferrugineum and R. hirsutum; in the Pyrenees by the R. ferrugineum only; and in the Caucasus by]*
