A study of the primary work of the folk artist Mathias Wernerus (1873-1931). Dickeyville Grotto, located in Dickeyville, Wisconsin, is an elaborate construction of concrete studded with glass, broken ceramics, marbles, and other materials. Niles (anthropology, Lafayette College) discusses the life of the artist, his sources of inspiration, the parish which he served as priest, his helpers, his materials, and the symbolism of the grotto. Includes 40 color photos. No index. Annotation c. by Book News, Inc., Portland, Or.