These fabulous beings are of many kinds, and have various characteristics; there are jinns, in whose veins runs fire instead of blood, who once inhabited the earth, but sinned and were driven away by the angels of God; Sheytans, who are children of Iblis, the Devil; Afreets, Marids; and Ghouls, who are female demons and live among deserts and graveyards, assuming various forms and luring men to death. These creatures are usually found in caves, tombs, wells, empty houses, latrines, and at cross roads. Sometimes they assume the shapes of men and sometimes they appear in the forms of domestic animals; in Siwa they are said to favour most the disguise of a cow. Among the most ignorant natives one meets with a decided reluctance to discuss things that are supernatural, but the more educated men are willing to speak of them. As in all countries the lower classes are the most credulous. For instance, in the case of certain old women who are reputed to be witches, the poor people avowedly believe in them, while the upper classes pretend not to; but when there is a birth or a wedding in the family of a sheikh, or a notable, they send presents to these old women saying that it is merely charity, although at heart they consider it safer to propitiate them in order to avert possible misfortune. It is rather like the lady in church who always bowed at the name of the Devil, because she thought it safer to be on the right side! The difference between the customs and superstitions of the Siwans and those of the Arabs on the desert which surrounds them is due to the fact that the former are of Berber origin. Their whole system of living is different, too. The Siwans are town dwellers whose dominant principle has been a sort of communism, whereas the Arabs are nomads, who adopted patriarchalism as their method of rule. The Siwans fought on foot, the Arabs were essentially cavalry. There are sheikhs in Siwa, but they are more like the members of a town council, while the real Arab sheikh corresponds to the feudal lord of the Middle Ages. It is strange to find the Siwans, with such a definite, different scheme of living, existing in the midst of a desert whose Arab population regards them almost as foreigners.