The connection with Dorians and their initiation festival apellai[clarification needed] is reinforced by the month Apellaios in northwest Greek calendars, but it can explain only the Doric type of the name, which is connected with the Ancient Macedonian word "pella" (Pella), stone. Stones played an important part in the cult of the god, especially in the oracular shrine of Delphi (Omphalos). The "Homeric hymn" represents Apollo as a Northern intruder. His arrival must have occurred during the "Dark Ages" that followed the destruction of the Mycenaean civilization, and his conflict with Gaia (Mother Earth) was represented by the legend of his slaying her daughter the serpent Python.