important link between the day-signs of the Mexican and Maya respectively, and the suggestion has been made by Seler that the Maya obtained these day-signs from the west via Oaxaca, calling attention to the comparatively simple nature of the Zapotec signs, which agree in this respect with those of Mexico. The Mexican valley as the place of origin of the day-signs may be, I think, disregarded, if only for the reason that certain of the animals serving as such do not occur in that region, and the choice therefore would lie between Oaxaca on the one hand and the central Mayan region on the other. Now the difference in form between the Mexican and Zapotec signs can be explained in many cases by the fact that the Zapotec term is equivocal. That being so, it seems to me obvious that the Zapotec must have borrowed from the Maya and not vice versa. My argument is as follows: The Zapotec signs are simple and obvious; those of the Maya are often highly conventionalized. It would be remarkable, therefore, that the Maya should have translated the Zapotec name in the wrong sense, while it would be perfectly natural for the Zapotec to have made a mistake and to have simplified the sign in accordance with their idea of the meaning of the term. If we add to this the fact that the only two initial dates discovered in the western Maya area are, together with the Chichen date, the latest known, the conclusion seems to me inevitable that early Maya culture, enumeration, and calendar spread together from Guatemala, through Oaxaca to the Tlalhuica country (Xochicalco) and the Mexican valley, becoming attenuated in the process. The question of the development of the calendar itself is interesting. The whole system seems to show traces of several modifications and to exemplify the efforts of a primitive people to adapt their chronology to solar time. The presence of five nemontemi or uayeb days over and above the period of 360 bears the stamp of an afterthought, while the 360-day period, of