The passes over these mountain ranges, giving access to the plateau-interior of Mexico from the oceans, vary from 8,500 feet to 10,000 feet, the range upon the Pacific side being generally the higher. But the highest peaks rise much above these altitudes, in some few cases reaching beyond the perpetual snow-line, although ever much lower than the Andes of South America. Three culminating peaks only pass the snow-line in Mexico, although others of the crests and summits are frequently snow-covered. The first of these three peaks is Orizaba, or Citlaltepetl--the "Star Mountain" of the native--the beautiful and symmetrically formed cone whose gleaming snow-cap is seen by the approaching traveller far over the stormy waters of the Gulf as he approaches the shores of Vera Cruz. So Grijalva and Cortes saw it; so the voyager of to-day sees it, as its snowy point seems to hang in mid-sky, its base buried in clouds and its gleaming summit surrounded by the azure of the tropic firmament. The summit of Orizaba is 18,250 feet above the level of the sea--the highest point in Mexico. Next in point of altitude is the famous Popocatepetl--the "Smoking Mountain," so called by the natives for its eruptions in centuries past, for it is no longer active. Some of the adventurous Spaniards of the band of Cortes reached the rim of the crater on its summit, and, indeed, later the Spaniards extracted sulphur therefrom, and various ascents have been made recently. Its last eruption was in 1665. The summit of Popocatepetl is 17,250 feet above sea-level, and it is of characteristic conical form. The third perpetually snow-capped peak is Ixtaccihuatl--the "Sleeping Woman," so named by the natives from the fanciful suggestiveness of a reclining woman--and its summit is 16,960 feet above the sea. The Indian names of these striking monuments of nature serve to show the poetical nomenclature which the natives of the Americas ever gave to topographical features. Especially was this the case among the Aztecs of Mexico and the Incas of Peru. The last-named mountain is not of the characteristic conical form which volcanoes generally have, its outline--beautiful as it is--forming a serrated edge, and it appeared singularly striking from Tacubaya, where I first beheld it. Nevertheless, all these three mountains--the highest points in the country--are of volcanic origin. The majestic and poetic peaks of the "Smoking Mountain" and the "Sleeping Woman" form part of the Sierra Nevada, or Cordillera of Anahuac, in company with Malinche, another of the highest culminating peaks, 14,630 feet above sea-level. This chain is a cross ridge of volcanic and more recent formation than that of the general system of the Mexican Cordilleras, and forms, as it were, a line of volcanic action at right angles to the general Andine trend, associated perhaps with Orizaba on the east and the volcano of Colima (12,990 feet elevation) on the west. This latter mountain is the