THE NUER OF THE SOUTHERN SUDAN 275
An aggregate of villages lying within a radius which allows easy inter-communication we call a 'district'. This is not a political group, for it can only be defined in relation to each village, since the same villages may be included in more than one district; and we do not regard a local community as a political group unless the people who comprise it speak of themselves as a community by contrast with other communities of the same kind and are so regarded by outsiders. Nevertheless, a district tends to coincide with a tertiary tribal section and its network of social ties are what gives the section much of its cohesion. People of the same district often share common camps in the drought and they attend one another's weddings and other ceremonies. They intermarry and hence establish between themselves many affinal and cognatic relationships which, as will be seen later, crystallize round an agnatic nucleus.
Villages, the political units of Nuerland, are grouped into tribal sections. There are some very small tribes to the west of the Nile which comprise only a few adjacent villages. In the larger tribes to the west of the Nile and in all the tribes to the east of it, we find that the tribal area is divided into a number of territorial sections separated by stretches of unoccupied couritry, which intervene also between the nearest habitations of contiguous tribes.
As all Nuer leave their villages to camp near water, they have a second distribution in the dry season. When they camp along a river, these camps sometimes succeed one another every few miles, but when they camp around inland pools, twenty to thirty miles often separate one camp from the next. The territorial principle of Nuer political structure is deeply modified by seasonal migration. People who form separate village communities in the rains may unite in a common camp in the drought. Likewise, people of the same village may join different camps. Also, it is often necessary, in the larger tribes, for members of a village to traverse wide tracts of country, occupied by other village communities, to reach water, and their camp may lie close to yet other villages. To avoid the complete loss of their herds by rinderpest or some other misfortune, Nuer often distribute the beasts in several camps.
In western Nuerland, where the tribes are generally smaller than to the east of the Nile, there is usually plenty of water and