Again, a long acquaintance with many tribes in their homes leads to the belief that savage people do not lack industry so much as wisdom. They are capable of performing, and often do perform, great and continuous labor. The men and women alike toil from day to day and from year to year, engaged in those tasks that are presented with the recurring seasons. In civilization, hunting and fishing are often considered sports, but in savagery they are labors, and call for endurance, patience, and sagacity. And these are exercised to a reasonable degree among all savage peoples. It is probable that the real difficulty of purchasing quantities of food from Indians has, in most cases, not been properly understood. Unless the alien is present at a time of great abundance, when there is more on hand or easily obtainable than sufficient to supply the wants of the people, food can not be bought of the Indians. This arises from the fact that the tribal tenure is communal, and to get food by purchase requires a treaty at which all the leading members of the tribe are present and give consent. As an illustration of the improvidence of the Indians generally, the habits of the tribes along the Columbia River may be cited. The Columbia River has often been pointed to as the probable source of a great part of the Indian population of this country, because of the enormous supply of salmon furnished by it and its tributaries. If an abundant and readily obtained supply of food was all that was necessary to insure a large population, and if population always increased up to the limit of food supply, unquestionably the theory of repeated migratory waves of surplus population from the Columbia Valley would be plausible enough. It is only necessary, however, to turn to the accounts of the earlier explorers of this region, Lewis and Clarke, for example, to refute the idea, so far at least as the Columbia Valley is concerned, although a study of the many diverse languages spread over the United States would seem sufficiently to prove that the tribes speaking them could not have originated at a common center, unless, indeed, at a period anterior to the formation of organized language.