Postponing for the present further discussion of this, the most precious and remarkable monument which has ever been unearthed on the American Continent, let us briefly bestow attention upon the two other monoliths which may be said to be its companions and obviously belong to the same period and civilization. In 1886, in the preliminary note cited above, I advanced the view that the first of these, generally known as the “Sacrificial stone,” was a “law-stone of a similar nature [to the Calendar-stone] which recorded, however, the periodical collection of certain tributes paid by subjugated tribes and others whose obligation it was to contribute to the commonwealth of Mexico.” I pointed out that the “frieze around the stone consists of groups, placed at intervals, of the flint-knives (tecpatl) with conventionally carved teeth (tlantli) giving in combination the word ‘tecpatlantli.’ This occurs in Sahagun’s Historia, as the name given to the ‘lands of the tecpan or palace,’ and in one of the native works I find designated the four channels into which the produce of these lands was diverted.” I likewise noted that “the periods indicated on it differ from those on the Calendar-stone,” which might more appropriately be designated as the ancient Mexican wheel of the law or of the Great Universal Plan. Thirteen years of painstaking research have only served to strengthen me in my interpretation of the “Sacrificial-stone.” The frieze around it exhibits sixteen groups, each consisting of the repeated representation of a warrior characterized by having one foot only. In each case he is figured as seizing by the hair a different individual, who bows his head and offers the weapon he holds in his right hand to his victor. Amongst the sixteen subjugated personages are two women and above each are hieroglyphs expressing the names of well-known localities, some of which are mentioned in native chronicles as having been conquered in historical times by Mexican rulers. In my account of the Plan of the Ancient City of Mexico, I shall illustrate these hieroglyphs, locate the places to which they refer and further discuss this monument. Meanwhile I shall but state that it undoubtedly belongs to the same category of monuments as the tablets in the “Temple of the Sun” at Palenque; the bas-relief at Ixkun and that in the house of the “Tennis-court” at Chichen-Itza where warriors in a procession render homage to a seated personage, by presenting their spear-throwers to him in precisely the same manner as shown on the Mexican Tribute-Stone.