In the second place, when a general clearance of evils is resorted to periodically, the interval between the celebrations of the ceremony is commonly a year, and the time of year when the ceremony takes place usually coincides with some well-marked change of season—such as the close of winter in the arctic and temperate zones, and the beginning or end of the rainy season in the tropics. The increased mortality which such climatic changes are apt to produce, especially amongst ill-fed, ill-clothed, and ill-housed savages, is set down by primitive man to the agency of demons, who must accordingly be expelled. Hence, in New Britain and Peru, the devils are or were driven out at the beginning of the rainy season. When a tribe has taken to agriculture, the time for the general expulsion of devils is naturally made to agree with one of the great epochs of the agricultural year, as sowing or harvest; but, as these epochs themselves often coincide with changes of season, it does not follow that the transition from the hunting or pastoral to the agricultural life involves any alteration in the time of celebrating this great annual rite. Some of the agricultural communities of India and the Hindoo Koosh, as we have seen, hold their general clearance of demons at harvest, others at sowing-time. But, at whatever season of the year it is held, the general expulsion of devils commonly marks the beginning of the new year. For, before entering on a new year, people are anxious to rid themselves of the troubles that have harassed them in the past; hence the fact that amongst so many people—Iroquois, Tonquinese, Siamese, Tibetans, etc.—the beginning of the new year is inaugurated with a solemn and public banishment of evil spirits.