Under irrigation, smaller areas need to be cultivated for the same crop returns, for it has been amply demonstrated that the acre yields under proper irrigation are very much larger than the best yields under the most careful system of dry-farming. Secondly, a greater variety of crops may be grown on the irrigated farm than on the dry-farm. As has already been shown in this volume, only certain drouth resistant crops can be grown profitably upon dry-farms, and these must be grown under the methods of extensive farming. The longer growing crops, including trees, succulent vegetables, and a variety of small fruits, have not as yet been made to yield profitably under arid conditions without the artificial application of water. Further, the irrigation-farmer is not largely dependent upon the weather and, therefore, carries on this work with a feeling of greater security. Of course, it is true that the dry years affect the flow of water in the canals and that the frequent breaking of dams and canal walls leaves the farmer helpless in the face of the blistering heat. Yet, all in all, a greater feeling of security is possessed by the irrigation farmer than by the dry-farmer. Most important, however, are the temperamental differences in men which make some desirous of giving themselves to the cultivation of a small area of irrigated land under intensive conditions and others to dry-farming under extensive conditions. In fact, it is being observed in the arid region that men, because of their temperamental differences, are gradually separating into the two classes of irrigation-farmers and dry-farmers. The dry-farms of necessity cover much larger areas than the irrigated farms. The land is cheaper and the crops are smaller. The methods to be applied are those of extensive farming. The profits on the investment also appear to be somewhat larger. The very necessity of pitting intellect against the fierceness of the drouth appears to have attracted many-men to the dry-farms. Gradually the certainty of producing crops on dry-farms from season to season is becoming established, and the essential difference between the two kinds of farming in the arid districts will then he the difference between intensive and extensive methods of culture. Men will be attracted to one or other of these systems of agriculture according to their personal inclinations. The scarcity of water