Originally transmitted orally, genealogies or family histories were a way of tracing the descent of a race or people through its ruling dynasty from a figure or deity from whom the race took its name. They were often purely speculative about the earliest generations because of the artificial purpose they served — to show continuity from an illustrious ancestor to the present day. As well as tracing the origins of a race, the pedigree or family tree bound its members in a close sense of kinship, reinforced by its recitation on ceremonial occasions, normally in a poetic or chronicle form that was easy to memorise. The Ashanti and Yoruba tribes of West Africa have their own hereditary tribal historian whose function it is to preserve these genealogical traditions, while in Scotland, the 'Lord Lyon King of Arms' remains the genealogist for all the clans. A Scottish clan is composed of the descendants of an actual or mythical ancestor, the chief of the clan being the senior male descendant in direct line. Each clan was originally organised on a territorial basis, which helped the family historian to discover at least which part of the country his antecedents stemmed from. For a clan member, a knowledge of his own genealogy and that of his chief was an integral part of his life, although no written record of it might exist. Family celebrations were the occasion for the recital of pedigrees to stress the unity and history of the line.