Fi-fi is supposed to be a spirit always invisible and occasionally audible. It is considered a bringer of both good and bad luck, but although this is so no attempt is made to propitiate it. The cult indeed is so absurd that the wonder is that the people believe in it at all; yet, although there is apparently nothing supernatural on the face of it, the Papuans are willing to credit its manifestations. When a tribe wishes to know its luck, and when a hostile attack is imminent, it has recourse to the rites of Fi-fi; these are always celebrated at night. The crowd gathers round the fire, and the girl who is supposed to be the medium of the power is told off to communicate with Fi-fi; from that moment, by a peculiar confusion in their minds between the spirit and the medium, she becomes Fi-fi to all intents and purposes. She retires to some corner near at hand, where she is not seen, and from there she whistles in different keys. The sound is made entirely at the medium’s discretion, but the moment it is heard the people exclaim that Fi-fi has come, and they judge by the whistling whether the omens are favourable or not. They would seem to have an idea of two Fi-fis, for the girl’s first call is two short notes repeated. No immediate answer comes, and the people round the fire remark casually to each other that the other Fi-fi has not heard, but they say, “Gua-fua”—that is, “Wait.” The girl whistles again, and in a moment or two answers herself; then the listeners round the fire exclaim, “Oi-kai-yoi, Fi-fi-mai” (“You hear, Fi-fi has come”). Occasionally we have said to them, “Tell Fi-fi to speak,” but they refused point-blank; and when we asked them why they did not bring Fi-fi, they said they could not. The priestess varied her whistle, and then interpreted her own messages. Once a woman is chosen to communicate with Fi-fi, she retains the office for life. This form of divination occurred most frequently at Waley. The priestess is not above the Delphic trick of framing her oracles to suit political necessity or her own inclinations and likings. One would think that people of such general common sense as the Papuans would see the possibility of deception, but they have implicit faith in Fi-fi’s manifestations. Certain insects, I noted, were also regarded as “Fi-fi.” When a particular species of fire-fly entered the house at night the natives immediately predicted bad luck, or impending attack and extermination by hostile tribes. This failure of intelligence at one point is paralleled by their inability to grasp the simplest idea of number. Further than three they cannot count, although we often tried, by means of their ten fingers, to instil some notions of a higher calculus into them.