It would seem that the duration of certain religious festivals was fixed to commemorate the existence on Earth of these _seven_ primitive gods or rulers, the tradition of which we find in all countries where we meet with vestiges of the Mayas. So we see the _seven days_ of the festival of the Eleusinian mysteries; the _seven days_ of the festival in honor of the bull Apis, a symbol of Osiris; the _seven days_ of the feast of the tabernacles. The septenary system was also adopted for the same purpose no doubt, in Mayax, since we find the _seven_ cities dedicated to each of the members of king Can's family; the _seven_ pyramids that adorned the city of Uxmal; the _seven_ turrets that ornamented the south façade of the north wing of king Can's palace at Uxmal, each turret inscribed with the name of one of the members of his family; those dedicated to the females being on the east end of the wing. The _seven gradients_ into which is divided the third or uppermost of the three platforms that serve as a substructure to the temples and palaces; the _seven superposed gradients_, forming all the pyramids calling to mind the _seven terraces_ of the temple of the _seven_ lights at Borsippa, the most perfect form of Chaldee "temple tower," and the "pyramid degrees" at Sakkara, although in this Egyptian pyramid the gradients are more numerous. The _seven rooms_ built on the west side of the conical mound that supports the temple in which the mysteries were performed at Uxmal: each room again being dedicated to one of the members of king Can's family; the bust of the person to whom it was consecrated being affixed over the doorway. The _seven courses_ of the stones used in the construction of the walls and of the triangular arches that form the ceilings of the rooms. The same system prevails in the arrangement of the grand gallery in the centre of the great pyramid at Ghizzeh in Egypt. In that monument as in all the antique edifices of Mayax, the proportional scale followed by the architects in the drawing of their plans is in accordance with the numbers 3, 5, 7, and their multiples.