We met a jaunty-looking party in the valley, two women and five or six men, all on good horses, and dressed in the extreme of fashion which the Mexican ranchero affects—­broad-brimmed hats with costly gold and silver serpents for hat-bands, and clothes and saddles glittering with silver.  Martin rode up to us as they passed, and said he knew them well for the boldest highwaymen in Mexico.  Had we started an hour or two later we should have met them in the forest, and have had an adventure to tell of.  As it was, the descent of three thousand feet had brought us from a land of thieves to a region where highway robbery is never known, unless when a party from the high lands come down on a marauding expedition.  It is an unquestionable fact that the Mexican robbers, whose exploits have become a matter of world-wide notoriety, all belong to the cold region of the plateaus, the tierra fria.  Once down in the tierra templada, or the tierra caliente, the temperate or the hot regions, you hear no more of them; or at least this is the case in the parts of Mexico we visited.  The reason is clear; it is only on the plateaus that the whites, preferring a region where the climate was not unlike that of Castile, settled in large numbers; so that it is there that Creoles and mestizos predominate, and they are the robbers.

We rode over great beds of gravel, cut up in deep trenches by the mountain-streams; then along the banks of the river, among plantations of tobacco, looking like beds of lettuces.  As we were riding along the valley, we saw before us a curious dark cloud, hanging over some fields near the river.  Our men, who had seen the appearance before, recognized it at once as a flight of locusts, and, turning out of the high-road, we came upon them just as they had settled on a clump of trees in a meadow.  They covered the branches and foliage until only the outline of the trees was visible, while the rest of the swarm descended on a green hedge, and on the grass.  As for us, we went and knocked them down with our riding-whips, and carried away specimens in our hats; but the survivors took no manner of notice of us, and in about ten minutes they left the trees mere skeletons, leafless and stripped of their bark, and moved across the field in a dense mass towards some fruit-trees a little way off.  For days after this, when we met with travellers on the road, or stopped at the door of a cottage to get a light or something to drink, and chatted a few minutes with the inhabitants, we found that our descent of the mountain-pass had brought us into a new set of interests.  News of the government and of the revolutionary party excited no curiosity,—­talk of robbers still less.  At every house the question was, “?_De donde vienen, Senores_?” “Where are you from, gentlemen?”—­and when we told them, “?_Y estaban alli las langostas_?” “And were the locusts there?” The whole country was being devastated by them; and the large