Fishing tribes have their chief occupation determined by their habitats, which are found along well stocked rivers, lakes, or coastal fishing grounds. Conditions here encourage an early adoption of sedentary life, discourage wandering except for short periods, and facilitate the introduction of agriculture wherever conditions of climate and soil permit. Hence these fisher folk develop relatively large and permanent social groups, as testified by the ancient lake-villages of Switzerland, based upon a concentrated food-supply resulting from a systematic and often varied exploitation of the local resources. The cooeperation and submission to a leader necessary in pelagic fishing often gives the preliminary training for higher political organization.[92] All the primitive stocks of the Brazilian Indians, except the mountain Ges, are fishermen and agriculturists; hence their annual migrations are kept within narrow limits. Each linguistic group occupies a fixed and relatively well defined district.[93] Stanley found along the Congo large permanent villages of the natives, who were engaged in fishing and tilling the fruitful soil, but knew little about the country ten miles back from the river. These two generous means of subsistence are everywhere combined in Polynesia, Micronesia and Melanesia: there they are associated with dense populations and often with advanced political organization, as we find it in the feudal monarchy of Tonga and the savage Fiji Islands.[94] Fisher tribes, therefore, get an early impulse forward in civilization;[95] and even where conditions do not permit the upward step to agriculture, these tribes have permanent relations with their land, form stable social groups, and often utilize their location on a natural highway to develop systematic trade. For instance, on the northwest coast of British Columbia and Southern Alaska, the Haida, Tlingit and Tsimshean Indians have portioned out all the land about their seaboard villages among the separate families or households as hunting, fishing, and berrying grounds. These are regarded as private property and are handed down from generation to generation. If they are used by anyone other than the owner, the privilege must be paid for. Every salmon stream has its proprietor, whose summer camp can be seen set up at the point where the run of the fish is greatest. Combined with this private property in land there is a brisk trade up and down the coast, and a tendency toward feudalism in the village communities, owing to the association of power and social distinction with wealth and property in land.[96] [Sidenote: Land bond in pastoral societies.]