Some few of these maps have interpretations annexed to them, which were obtained from the natives after the Conquest.[166] The greater part are without any, and cannot now be unriddled. Had the Mexicans made free use of a phonetic alphabet, it might have been originally easy, by mastering the comparatively few signs employed in this kind of communication, to have got a permanent key to the whole.[167] A brief inscription has furnished a clue to the vast labyrinth of Egyptian hieroglyphics. But the Aztec characters, representing individuals, or, at most, species, require to be made out separately; a hopeless task, for which little aid is to be expected from the vague and general tenor of the few interpretations now existing. There was, as already mentioned, until late in the last century, a professor in the University of Mexico, especially devoted to the study of the national picture-writing. But, as this was with a view to legal proceedings, his information, probably, was limited to deciphering titles. In less than a hundred years after the Conquest, the knowledge of the hieroglyphics had so far declined that a diligent Tezcucan writer complains he could find in the country only two persons, both very aged, at all competent to interpret them.[168] It is not probable, therefore, that the art of reading these picture-writings will ever be recovered; a circumstance certainly to be regretted. Not that the records of a semi-civilized people would be likely to contain any new truth or discovery important to human comfort or progress; but they could scarcely fail to throw some additional light on the previous history of the nation, and that of the more polished people who before occupied the country.[169] This would be still more probable, if any literary relics of their Toltec predecessors were preserved; and, if report be true, an important compilation from this source was extant at the time of the invasion, and may have perhaps contributed to swell the holocaust of Zumárraga.[170] It is no great stretch of fancy to suppose that such records might reveal the successive links in the mighty chain of migration of the primitive races, and, by carrying us back to the seat of their possessions in the Old World, have solved the mystery which has so long perplexed the learned, in regard to the settlement and civilization of the New.[171]