434 Traditions of the Baganda and Busho7igo.
These, it will be said, are ii priori considerations, which ought not to be allowed to colour our examination of the evidence. But in approaching it we cannot divest ourselves of experience acquired in other fields. That experience is greatly strengthened by the universal testimony to the shortness of collective memory of fact, when it is subjected to a rigid investigation. The continent of Africa, to which we must here confine ourselves, is inhabited by a large number of different races ; and the conditions of life and the structure of society present very wide differences. Yet there is on the whole a remarkable unanimity in the testi- mony of travellers, scientific explorers and missionaries, to the poverty of the ancestral history of the peoples who are not possessed of literary records. Estimates of the limit of really historical tradition among various tribes of Negroes and Bantu put it at about a hundred years, some- times at the utmost two hundred. If we count by the pedigree and assume the pedigrees to be true to fact, it comes to the same thing; for it is not common for a pedigree to contain more than from seven to ten names. So early are marriages that a pedigree of seven generations often might not represent much more than a century. But the pedigrees cannot be trusted. M. Junod, a very painstaking and judicious inquirer, in his recent work on the Thonga tribe, among which he has laboured as a missionary for many years, gives the genealogies of several chiefs. He has had the advantage of comparing them Vv^ith a Portuguese document, relating to the neighbourhood of Delagoa Bay, and dated in 1554. From this comparison it results that some of the names, not more than eight or ten steps backwards, were then already known as the names of clans and of rivers. Further he observes : " In the same clan there are sometimes variations [in the list] according to the informants. There may have been links omitted in the chain, because for the natives a grandson is a son, just as a son properly speaking. On the other hand, the law of
