A somewhat similar scattered location is found in arid deserts, where population is restricted to the oases dropped here and there at wide intervals amid the waste of sand. But unlike those fragments of human life on the frozen outskirts of the habitable world, the oasis states usually constitute links in a chain of connection across the desert between the fertile lands on either side, and therefore form part of a series, in which the members maintain firm and necessary economic relations. Every caravan route across the Sahara is dotted by a series of larger or smaller tribal settlements. Tripoli, Sokna, Murzuk, Bilma and Bornu form one such chain; Algiers, El Golea, Twat, the salt mines of Taudeni, Arawan and Timbuctoo, another. Bagdad, Hayil, Boreyda and Mecca trace the road of pilgrim and merchant starting from the Moslem land of the Euphrates to the shrine of Mohammed.[261] [Illustration: DISTRIBUTION OF SETTLEMENT IN THE NORWEGIAN PROVINCE OF FINMARKEN.] [Sidenote: Island way station on maritime routes.] Not unlike this serial grouping of oasis states along caravan routes through the desert are the island way stations that rise out of the waste of the sea and are connected by the great maritime routes of trade. Such are the Portuguese Madeiras, Bissagos, and San Thome on the line between Lisbon and Portuguese Loanda in West Africa; and their other series of the Madeiras, Cape Verde, and Fernando, which facilitated communication with Pernambuco when Brazil was a Portuguese colony. The classic example of this serial grouping is found in the line of islands, physical or political, which trace England's artery of communication with India--Gibraltar, Malta, Cyprus, Perim, Aden, Sokotra, and Ceylon, besides her dominant position at Suez. [Sidenote: Scattered location of primitive tribes.] Quite different from this scattered distribution, due to physical conditions, in an otherwise uninhabited waste is that wide dispersal of a people in small detached groups which is the rule in lower stages of culture, and which bespeaks the necessity of relatively large territorial reserves for the uneconomic method of land utilization characteristic of hunting, fishing, pastoral nomadism, and primitive agriculture. A distribution which claims large areas, without, however, maintaining exclusive possession or complete occupation, indicates among advanced peoples an unfinished process,[262] especially unfinished expansion, such as marked the early French and English colonies in America and the recent Russian occupation of Siberia. Among primitive peoples it is the normal condition, belongs to the stage of civilization, not to any one land or any one race, though it has been called the American form of distribution.