THE country of the Arapesh tribe is located in northwest New Guinea in the mandated territory of that island. Like most tribal countries of New Guinea, it can be traversed in a few days of hard walking. Parallel with the sea coast the Arapesh possess a strip of rich coastal plain running the length of a two days' walk. This plain extends inland less than a mile before the hills rise from it. Three native pads or" roads" cross the country inland over the foothills and over the main range of the Prince Alexander or Torricelli Mountains. These roads fall steeply over the main range and debouch on to a vast inland plain. The Arapesh tribe possesses only a narrow strip of this plain close to the hills, and not more than a day's walk long, parallel with the nearby Torricelli Mountains and with the more distant coast, which are themselves about two days' walk apart. The country is thus approximately two days' walk long on the coast, two days' walk in inland depth, and it narrows to one day's walk long on its inland base. A traveller encumbered with baggage and porters takes about a day longer in any direction of traverse of the country. This tribal country is a country of a common social culture, a common religion, a common technology, and a common language, despite petty differences of culture and of dialect, and despite the soil and climatic changes from coastal plain to hills to inland plain. The country of common culture has, however, no political unity. It is segmented by many internal war frontiers. Under conditions of present culture contact, warfare is sup-pressed, and some consciousness of tribal unity is developing in the larger labor centres where indentured laborers from many tribes meet. In the home country, however, a consciousness of political unity corresponding to the older and pre-existing cultural unity develops very slowly. The country of common culture, of no political unity, has some strange borders from a political viewpoint. For the borders are often exclusively cultural, and not coincident with war frontiers. These culture borders often divide a border sovereign locality into two segments of different culture and language peacefully, and without disturbance of its sovereignty. Peoples of other culture and language whose boundary meets an Arapesh culture boundary confine their warfare within their own culture, for the most part. Border sovereign units, whose members are divided in culture and in language, may be drawn as wholes into the internecine war machine of either culture, although the more aggressive culture of the two is likely to claim them the more in military matters. For example, the border village and locality of Ulupumaku contains the cultural and linguistic boundary