+497+. There are indications that the institutions of the Pueblo tribes (who are now wholly agricultural) have undergone modifications, perhaps under foreign (Spanish) influence. Hopi myths represent clans as descended from ancestors originally animal, and transformed into human shape by deities. But the elaborate sun-worship and the complicated solstice ceremonies are tribal.[850] The Zuñi economic ceremonies appear to have passed from under clan control. Thus, the magical ceremony for procuring rain, properly the function of the Frog clan, is now in the hands of rain-priests; and the magical, dramatic performances for insuring a supply of food are conducted by nontotemic religious fraternities. The great Snake "dance" may have been originally a totemic ceremony intended to secure rain and corn.[851] +498+. For a former totemic organization among the Navahos, Apaches, and Mohaves (these last live on the Colorado River) there are only vague traditions and other faint traces; the taboos on foods now touch not a particular clan but a whole tribe. +499+. The coast tribes of Northwest America (in British Columbia and the United States)[852] differ in social organization from the other Indians in several respects, and particularly in the importance they attach to rank, in their employment of the crest or badge, and in the prominence they give to the individual guardian animal or spirit. +500+. In the civil organization of the Carrier division of the Déné, the Salish, the Kwakiutl, and other tribes, three or four castes or groups are recognized: hereditary nobles; the middle class, whose position is based on property; and the common folk; and to these is to be added among some tribes the class of slaves. In the summer ceremonies the men are seated according to class and rank. The family pride of the nobles is great--every family has its traditions and pedigrees. In such a scheme the zoönymous clan plays an insignificant part. Classes and clans are mixed in the villages in which, for the most part, these people live, and trade is prominent in their life. The curious custom of the "potlatch"--a man invites his friends and neighbors to a gathering and makes them magnificent presents, his reputation being great in proportion to the extent of his gifts--appears to be a device for laying up property; the host in his turn receives presents from friends and neighbors.