Lest this hypothesis seem overstrained, analogies may be indicated. That which is initially sacred in a primitive cult frequently comes to have interrelations with the whole environment of its deities. Thus the worship of the oak by the Druids appears to have given an oak-like virtue to the oracular birds which dwelt in its branches, to the soil from which it grew, to the sky above it, to the priests who ministered to it and to the sacred implements they employed. The same may be said of the oak-cult of Zeus and the vine-cult of Dionysos. The numerous traditions which cluster round the ceremonial use of jade in China are eloquent of such a tendency. Thus trees, plants, animals, and natural objects are all in a manner identified and connected with the beautiful jade stone in its character as an imparter of vitality. Thus in the great worship of the gods whose cult was connected with obsidian, well-nigh everything with which it had interrelations came to partake of the nature of obsidian—grain, the earth, the atmosphere, the sun, the stars, the priesthood, blood, and rain. The process by which this Nahua cult became amalgamated with those of Tlaloc and Quetzalcoatl seems fairly clear. Upon their settlement on the Plateau of Anahuac it is plain from the terms of certain myths that the Nahua did not regard the cult of Quetzalcoatl in any friendly manner. Tezcatlipocâ is spoken of as driving him from the country, and it is probable that to begin with a certain amount of persecution may have been inflicted upon his adherents. But the Nahua would undoubtedly come to recognize the value of the calendar system connected with his cult, and it is clear that they did so from the fact that we find included in it certain of their principal gods. The final process of amalgamation probably took place during the eleventh and twelfth centuries, for, as seen at the Conquest period, the union of the three great cults of Mexico must have occupied several centuries. Such a duration of time was necessary for the development of a homogeneous and involved symbolism, which was obviously based on a tacit recognition of the unity of the Mexican faith. Initial disparities seem to be indicated principally by ancient traditions, of which perhaps the most notable was that which spoke of the different heavens of the three original cults, the Tlalocan of the worshippers of Tlaloc, the Tlapallan or over-sea paradise of the Quetzalcoatl cult, and the Sun-house or Valhalla of the Nahua. A striking proof of the adjustment of the chronology of the three cults may perhaps be found in the myths which speak of the existence of several “suns” or ages prior to the historical era, the “rulers” or patrons of which were, according to the most trustworthy sources, Tezcatlipocâ, Quetzalcoatl, Tlaloc, and Chalchihuitlicue, goddess of the Tlaloc cult. [38]