In addition to the ordinary winter dwellings, which are usually occupied by two or more families, each village is commonly supplied with an assembly house or _casine_ (a word of Russian origin), which serves also as a bath-house, and in them winter dances, the chief amusement of the people, are held. The casine, built by the united efforts of the various members of a community, consist of a single room, in part underground and entered by a tunnel, which frequently measures some 25 by 30 feet on the sides, and is approximately 15 feet high. They are substantially made of logs or of thick planks hewn with much labour from stranded tree trunks. The roof is of logs covered with moss and earth, and has an opening in the centre for the escape of smoke from the fire kindled on a hearth in the centre of the floor. When the fire is not burning, the opening in the roof is closed with a membrane obtained from the intestines of the seal. About the sides of the room there is a raised platform for spectators during dances and for the use of bathers when the customary steam-baths are indulged in. An interesting fact in connection with both the ordinary winter homes and the casines, which indicates their American origin, is that they are communal. A tenement used by several families in common is characteristic of the American aborigines from the arctic to Panama. The architecture of the Innuits has been modified but little during recent years, except that in localities most visited by white men and where trading stations have been established, as at St. Michael, log-houses built after the manner of those used by the Russian residents have to a considerable extent replaced the native huts, with favourable results so far as sanitary conditions are concerned. The Russian log-house is not unlike the many similar structures still to be seen in portions of Canada and the United States, except that the upper side of each log is hewn so as to have a sharp edge, which fits into a deep groove, cut in the log which rests on it. Moss is placed between the logs, and is also used to fill all holes and crevices. Air is usually admitted through a pipe situated beneath the floor and opening in front of the stove, if one is used, and a small pipe for ventilation passes out through the roof. In the Russian houses the stove is usually a huge affair, made of large flat stones, which retain heat for a long time. [Illustration: PLATE VI.--Linguistic stocks of indians north of Mexico.]