The triple form is not primitive, it is merely an instance of a general tendency, to be discussed later—a tendency which makes of each woman-goddess a trinity, which has given us the Horae, the Charites, the Semnae, and a host of other triple groups. It is immediately obvious that the triple Gorgons are not really three but one + two. The two unslain sisters are mere superfluous appendages due to convention; the real Gorgon is Medusa. It is equally apparent that in her essence Medusa is a head and nothing more; her potency only begins when her head is severed, and that potency resides in the head; she is in a word a mask with a body later appended. The primitive Greek knew that there was in his ritual a horrid thing called a Gorgoneion, a grinning mask with glaring eyes and protruding beast-like tusks and pendent tongue. How did this Gorgoneion come to be? A hero had slain a beast called the Gorgon, and this was its head. Though many other associations gathered round it, the basis of the Gorgoneion is a cultus object, a ritual mask misunderstood. The ritual object comes first; then the monster is begotten to account for it; then the hero is supplied to account for the slaying of the monster. Ritual masks are part of the appliances of most primitive cults. They are the natural agents of a religion of fear and ‘riddance.’ Most anthropological museums[484] contain specimens of ‘Gorgoneia’ still in use among savages, Gorgoneia which are veritable Medusa heads in every detail, glaring eyes, pendent tongue, protruding tusks. The function of such masks is permanently to ‘make an ugly face,’ _at_ you if you are doing wrong, breaking your word, robbing your neighbour, meeting him in battle; _for_ you if you are doing right. Scattered notices show us that masks and faces were part of the apparatus of a religion of terror among the Greeks. There was, we learn from the lexicographers[485], a goddess Praxidike, Exactress of Vengeance, whose images were heads only, and her sacrifices the like. By the time of Pausanias[486] this head or mask goddess had, like the Erinys, taken on a multiple, probably a triple form. At Haliartos in Boeotia he saw in the open air ‘a sanctuary of the goddesses whom they call Praxidikae. Here the Haliartans swear, but the oath is not one that they take lightly.’ In like manner at ancient Pheneus, there was a thing called the Petroma[487] which contained a mask of Demeter with the surname of Cidaria: by this Petroma most of the people of Pheneus swore on the most important matters. If the mask like its covering were of stone, such a stone-mask may well have helped out the legend of Medusa. The mask enclosed in the Petroma was the vehicle of the goddess: the priest put it on when he performed the ceremony of smiting the Underground Folk with rods. [Illustration: FIG. 28.] [Illustration: FIG. 29.] [Illustration: FIG. 30.] [Illustration: FIG. 31.]