The employment of domestic animals distinguished the Peruvians from the other races of the New World. This economy of human labor by the substitution of the brute is an important element of civilization, interior only to what is gained by the substitution of machinery for both. Yet the ancient Peruvians seem to have made much less account of it than their Spanish conquerors, and to have valued the llama, in common with the other animals of that genus, chiefly for its fleece. Immense herds of these "large cattle," as they were called, and of the "smaller cattle," 3 or alpacas, were held by the government, as already noticed, and placed under the direction of shepherds, who conducted them from one quarter of the country to another, according to the changes of the season. These migrations were regulated with all the precision with which the code of the mesta determined the migrations of the vast merino flocks in Spain; and the Conquerors, when they landed in Peru, were amazed at finding a race of animals so similar to their own in properties and habits, and under the control of a system of legislation which might seem to have been imported from their native land.4 But the richest store of wool was obtained, not from these domesticated animals, but from the two other species, the huanacos and the vicunas, which roamed in native freedom over the frozen ranges of the Cordilleras; where not unfrequently they might be seen scaling the snow- covered peaks which no living thing inhabits save the condor, the huge bird of the Andes, whose broad pinions bear him up in the atmosphere to the height of more than twenty thousand feet above the level of the sea.5 In these rugged pastures, "the flock without a fold" finds sufficient sustenance in the ychu, a species of grass which is found scattered all along the great ridge of the Cordilleras, from the equator to the southern limits of Patagonia. And as these limits define the territory traversed by the Peruvian sheep, which rarely, if ever, venture north of the line, it seems not improbable that this mysterious little plant is so important to their existence, that the absence of it is the principal reason why they have not penetrated to the northern latitudes of Quito and New Granada.6