The fact is now established, however, that pictographic records covering periods of from sixty to perhaps two hundred years or more do, or did, exist among several tribes, and it is entirely probable that every leading mother tribe had such a record of its origin and wanderings, the pictured narrative being compiled by the priests and preserved with sacred care through all the shifting vicissitudes of savage life until lost or destroyed in the ruin that overwhelmed the native governments at the coming of the white man. Several such histories are now known, and as the aboriginal field is still but partially explored, others may yet come to light. THE WALAM OLUM OF THE DELAWARES East of the Mississippi the most important and best known record is the Walam Olum or "red score" of the Delawares, originally discovered in 1820, and published by Dr D.G. Brinton in 1885. It consists of a series of pictographs designed to fix in memory the verses of a genesis and migration chant which begins with the mythic period and comes down to the advent of the whites about the year 1610. It appears to be genuine and ancient, although the written chant as we find it contains modern forms, having of course been reduced to writing within a comparatively recent period..