The various points discussed here were brought out by a study of the pottery found in 1931-32 at the Maya Old Empire site of Piedras Negras, Peten, Guatemala, butwere not included in the report on that material (M. Butler, Piedras Negras Pottery, Piedras Negras Preliminary Papers, University [of Pennsylvania] Museum, No. 4, 1935), sincethey were theoretical matters, of general rather than specific interest. They were discussed in an unpublished, philosophical, Introduction which served to make the report acceptable to the Department of Anthropology of the University of Pennsylvania as the writer's doctoral dissertation. Another section of this Introduction has been published as Pottery Study in the Maya Area (American Antiquity, Vol. 2, No. 2, 1936, in press).