THE scientific value of the anthropological series of the Publications of the Field Columbian Museum, Chicago, has been sustained by the important memoir on the Arapaho sun dance by Dr. G. A. Dorsey, the energetic curator of the Department of Anthropology. Although only very recently published, the work bears the date of June, 1903, which will cause superfluous trouble to bibliographers. Dr. Dorsey witnessed the sun dance in 1901 and 1902, and he has taken great pains to give a clear and minute account of this eight-day ceremony. The description is illustrated with a great wealth of illustrations, there being no fewer than 135 plates, many of which contain two figures; it is probably safe to say that no ceremony has hitherto been so amply illustrated. It is also a matter of congratulation that the description is so detailed, as the significance of a ceremony can only be adequately realised when all the details of the events are carefully recorded. We can heartily congratulate the author and the museum authorities on the publication of this authoritative memoir. More information would, however, be welcome as to the precise part taken by the several social groups of the Arapaho in this national festival, as this is usually an important element in social ritual. Apparently the ceremony may take place at any time, but it is generally during the winter. It is performed in compliance with a vow.