58 AFRICAN POLITICAL SYSTEMS
mainly by Kaa, Phaleng, and Kgalagadi; Matshana and Maga-lapye by Herero and Kgalagadi; Tswapong by Tswapong, with smaller groups of Birwa, Rotse, and Seleka; Bobonong by Birwa; Mmadinare by Talaote, Seleka, and Tswapong; Tonota by Khurutshe and Kalaka; BoKalaka by Kalaka; and BoTletle and Matsha by many small groups of Kalaka, Khurutshe, Herero, Kuba, Nabya, Subia, and Kgalagadi. The Sarwa are not confined to any particular district, but are scattered widely over the whole reserve.
The inhabitants of a small village generally belong to the same tribal community. For administrative purposes they are held to constitute a single 'ward' (motse, Village'), under the leadership and authority of an hereditary headman. The ward is a patrilineal but non-exogamous body, most of whose members belong to the family-group of the headman, but normally it also includes several other families or family-groups1 attached to him as dependants. The bigger settlements all contain a number of wards, not necessarily of the same community. The village in such cases must be regarded, not as a local unit divided for convenience into smaller segments, but as a cluster of self-contained social groups inhabiting one centre. Within it each ward has its own hamlet, clearly separated from the rest, and its own kgotla (council-place), where lawsuits and other local business are dealt with. Altogether there are some 300 wards in the tribe, of which no less than 113 are located in Serowe. They vary considerably in size, but on the average contain from 200 to 400 people each.
This grouping into wards, common to all the Tswana, explains the facility with which immigrants or conquered peoples were absorbed into the tribe. Single families or family-groups of strangers were placed by the chief in some existing ward, i,e. under the immediate control of a particular ward-head. A larger group would be recognized as a separate ward in itself, with its leader as headman, or divided into a number of wards, according to its size and existing kinship or territorial organization. Every person in the tribe must belong to a ward and, save in exceptional circumstances, he must always live in the same place as his fellow members.
1 A family-group (kgotlana) is a collection of households whose heads are all descended in the male line from a common grandfather or great-grandfather. The senior descendant in line of birth is the 'elder' (mogolzvane) of the group.