While there are found in the mounds of the central Mississippi region, and also among the living natives of the North-west coast, resemblances to the art work of the Aztecs, Mayas, and other tribes of the Central-American region, there is no evidence that there was any approach, in these localities or elsewhere, to any kind of record to be compared with the proficiency of the South. What there may once have been in the way of writings on bark or wood we can only conjecture. The Davenport tablet has been pronounced, on good authority, to be within the powers of the Dakota tribes. Other tablets and inscriptions of the Eastern region are surrounded with doubt. The Mexican, that is, the Aztec, writing was more pictorial than that of the Mayas. It was cruder in every way, and comparing the two in the pages of Kingsborough and later reproductions, it is easy to distinguish a superior culture indicated by the writing of the Maya. We are more fortunate in the number of Aztec manuscripts preserved. The Spanish priests did what they could to obliterate the books existing when they came into the country, and Bishop Zumarraga made a fine bonfire out of a lot of them. But some escaped. Some priests sent copies or originals back home as curiosities, thinking, doubtless, that this took them out of the sight of the natives quite as effectually as the burning, and the natives themselves succeeded in preserving in secret some of the ancient documents. None of the oldest, however, have been found, but in time the number known to us may be considerably increased. One by one they turn up unexpectedly. That called the Codex Borgia was in use as a plaything of children of the Gustiniani family, till rescued by Cardinal Borgia, and only recently another one has been found dating from the year 1545,[60] wherein there are pictorial combinations never before seen. Thus gradually our data are increasing, and with the awakening interest in Amerindian archæology that seems to have come in these latter days of the nineteenth century, a century that has let slip much valuable data never to be recovered, further finds may be expected from time to time. The style of the Aztec documents is different from that of the Maya and Brinton believes them to be independent developments. It is possible, however, that both were derived from the same source and developed independently.[61] The Aztec writing is of a “rebus” character, and Brinton has applied to it the term _ikonomatic_, which he explains as follows in his _Essays of an Americanist_[62]: “All methods of recording ideas have been divided into two classes—Thought Writing and Sound Writing. The first, simplest and oldest, is Thought Writing. This in turn is subdivided into two forms—Ikonographic and Symbolic Writing. The former is also known as Imitative, Representative, or Picture Writing. The object to be held in memory is represented by its picture drawn with such skill, or lack of skill, as the writer may possess.