ANNOTATIONS AND ADDITIONS. 157 



perate zone, in the Alps (lat. 45|), Pinus picea (Du Roi) 

 advances highest, leaving the birches behind ; and in the 

 Pyrenees (lat. 42J), Pinus uncinata (Earn.) and P. sylves- 

 tris vat. rubra: within the tropics, in lat. 19 20, in 

 Mexico, Pinus Montezumse leaves far behind Alnus toluc- 

 censis, Quercus spicata, and Q. crassipes ; while in the snow 

 mountains of Quito at the equator, Escallonia myrtilloides, 

 Arah'a avicennifolia, and Dryinis 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 Expedi- 

 tion in 1577, to the northern highlands of Mexico; or 

 through a range of 86 degrees of latitude, or 5160 geogra- 

 phical 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 the/ 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 Ericaceae, 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 Py- 

 renees by the R. ferrugineum only ; and in the Caucasus by 



