When, some years ago we undertook to examine the argument of Señor Perez we were not at all astonished by the great antiquity of the date he had drawn from the Maya Manuscript. For, nearly at the same time, we had reached similar results in an attempt made to utilize certain records which Ixtlilxochitl (1590), and Veytia (1760), (Kingsborough Collection, Vols. 8 and 9), have left regarding the earliest chronology of the Nahuatl tribes. By adopting a more rational method of computation than these Mexican writers had followed, we were unable to withstand the conclusion, that the Nahuatl people who were immediate territorial neighbors of the Mayas, considered the year 258 A. D. the earliest date of their arrival on and occupancy of the Mexican soil. Thus we had reached in this line of investigation very nearly the same results with the Nahuatl as Señor Perez with the Maya chronology, and the suspicion began to dawn upon us that these two neighboring people might, possibly, have stood in a still closer than a mere territorial connection. These results, however, were only of a very problematical nature. They were derived from written reports, which, after all, could not be regarded as unquestionable authority. But they received a strong confirmation from a discovery we made later on the so-called Mexican Calendar Stone. In our discussion of this monument we believe that we have given ample proof of the fact, that its principal zone contains a sculptured record, showing a series of numerical symbols, from the computation of which the year 231 A. D. resulted as that which the Nahuatls had accepted as the first date of their national era. Records presented in stone and compiled by the nation whose history they convey, must always be considered the most authentic evidence of historical truth. Now, were we also so fortunate as to possess some Maya monument, similar to the Mexican Calendar Stone, and were we also able to decipher it, we should thereby have the means for determining whether Maya chronology extended back to an epoch different from that of the Nahuatl, or to one identical with it. That such a monument once existed we have no doubt. That it may still exist, we have no reasonable grounds for denying the possibility. It remains, however, still to be discovered and to be interpreted. But since the fortunate discovery has not yet been made, we must rest satisfied for the present with conclusions derived from extant written records. The only manuscript of this character thus far brought to light, is that said to have been found at Mani,[31] which was translated by Señor Perez from the Maya language, and accompanied by a very valuable chronological interpretation.