Since moving on from point to point in early times was so much the habit of all Indians, the marvel is that these migrating bands stopped in a region so unpromising and infertile as the Great Basin, where the human struggle for existence is of such incalculable proportion that the imagination grows weary; but stop they did, as innumerable pueblo ruins bear tangible witness. By its very aridity the sedentary Indians were assured of a certain protection from their enemies, who would not be so much attracted to the desert as to more luxuriant regions.[120] True, this land of sage and sand, of greasewood and the burning sun, can be made to flower like a garden, with sufficient water, but the infinite labor required daunts the mind. Since the outcome of migration is more or less permanent settlement, some allusion to the adaptation of the Indian to the natural environment in which he elected to remain is pertinent here. If upon the flat plain, his adobe of pinkish yellow or brown sinks into the sandy background and seems a mere outcropping of the rounded hills close by; if upon the mesa-top, the houses look as if carved from the cliff itself and defy all approach. The lack of all domestic animals among the Pueblos, a notable fact, was of course a very serious handicap to them. Until the Spaniards brought the horse and the sheep into the country in the sixteenth century, the infrequent dog left behind by the nomad tribes and used by the Pueblos as an accompaniment of the chase was their only four-footed domestic animal. Castañeda notes as an uncommon sight the wolfish dog which the Plains Indians harnessed to carry heavy burdens of transport.[121] He also wrote that the pueblo people assured him they kept the turkey only for its eggs and its feathers, but he could not believe it, since the Spaniards found that bird such good eating. Other points of contrast between the sedentary and nomad Indians are full of interesting suggestion. But we can here indicate only in a superficial way the most patent of them all. The Pueblo Indians, having established themselves in a latitude and at an altitude highly favorable to civilization, made more rapid progress in agriculture and the arts than their kindred “nations” farther north. But on the other hand, wandering over great distances trained the nomad Indian to much greater quickness of eye and other sense perceptions, and also developed a more sinewy and alert body. Change of scene increased his knowledge of other parts of the continent and taught him how to cope with innumerable difficulties on the way, of which the Pueblo Indian knew nothing.