- [Footnote: are hailed with joy by those who come from the sea-coast,
as indicating a climate where, so far as experience has hitherto shewn, the deadly malady of the black vomit (Vomito prieto, a form of yellow fever) does not reach. The lower limit of oaks, and more particularly of the Quercus xalapensis (one of the 22 Mexican species of oak first described by us), is on the road from Vera Cruz to the city of Mexico, a little below the Venta del Encero, 2860 (3048 E.) feet above the sea. On the western side of the highlands between the city of Mexico and the Pacific, the limit is rather lower down, for oaks begin to be found near a hut called Venta de la Moxonera, between Acapulco and Chilpanzingo, at an absolute elevation of 2328 (2480 E.) feet. I found a similar difference in the height of the lower limit of pine woods on the two-sides of the continent. On the Pacific side, in the Alto de los Caxones north of Quaxiniquilapa, we found this limit for Pinus Montezumæ (Lamb.), which we at first took for Pinus occidentalis (Swartz), at an elevation of 3480 (3709 E.) feet; while towards Vera Cruz, on the Cuesta del Soldado, pines are first met with at a height of 5610 (5950 E.) feet. Therefore both the kinds of trees spoken of above, oaks and pines, descend lower on the side of the Pacific than they do on the side of the Antillean sea. In ascending the Cofre di Perote, I found the upper limit of the oaks 9715 (10354 E.) feet, and that of the Pinus Montezumæ at 12138 (12936 E.) feet above the sea, or almost 2000 (2132 E.) feet higher than the summit of Etna. Considerable quantities of snow had fallen at this elevation in the month of February.]*
