The path was steep and exceedingly rough. Thick matted bushes covered its surface, and the winter torrents had broken it into deep stony channels, hardly practicable for the passage of artillery, while the straggling branches of the trees, flung horizontally across the road, made it equally difficult for cavalry. The cold, as they rose higher, became intense. It was keenly felt by the Spaniards, accustomed of late to a warm, or at least temperate, climate; though the extreme toil with which they forced their way upward furnished the best means of resisting the weather. The only vegetation to be seen in these higher regions was the pine, dark forests of which clothed the sides of the mountains, till even these dwindled into a thin and stunted growth. It was night before the way-worn soldiers reached the bald crest of the sierra, where they lost no time in kindling their fires; and, huddling round their bivouacs, they warmed their frozen limbs and prepared their evening repast. With the earliest dawn, the troops were again in motion. Mass was said, and they began their descent, more difficult and painful than their ascent on the day preceding; for, in addition to the natural obstacles of the road, they found it strewn with huge pieces of timber and trees, obviously felled for the purpose by the natives. Cortés ordered up a body of light troops to clear away the impediments, and the army again resumed its march, but with the apprehension that the enemy had prepared an ambuscade, to surprise them when they should be entangled in the pass. They moved cautiously forward, straining their vision to pierce the thick gloom of the forest, where the wily foe might be lurking. But they saw no living thing, except only the wild inhabitants of the woods, and flocks of the _zopilote_, the voracious vulture of the country, which, in anticipation of a bloody banquet, hung, like a troop of evil spirits, on the march of the army. As they descended, the Spaniards felt a sensible and most welcome change in the temperature. The character of the vegetation changed with it, and the funereal pine, their only companion of late, gave way to the sturdy oak, to the sycamore, and, lower down, to the graceful pepper-tree mingling its red berry with the dark foliage of the forest; while, in still lower depths, the gaudy-colored creepers might be seen flinging their gay blossoms over the branches and telling of a softer and more luxurious climate.