We are justified in accepting the theory that sun and moon[14] worship is usual among primitive men. Whether that of the sun or of our satellite was the earlier it is not in the province of this article to discuss, but it is doubtless true that sun worship is a very ancient cult among most primitive peoples. The Pueblos are not exceptions, and while we can not say that their adoration is limited to the sun, it forms an essential element of their ritual, while their anhydrous environment has led them into a rain-cloud worship and other complexities. I think we can safely say, however, that the germ of their astronomy sprang from observations of the sun, and while yet in a most primitive condition they noticed the fact that this celestial body did not always rise or set at the same points on the horizon. The connection between these facts and the seasons of the year must have been noted early in their history, and have led to orientation, which plays such an important part in all their rituals. Thus the approach of the sun to a more vertical position in the sky in summer and its recession in winter led to the association of time when the earth yielded them their crops with its approach, and the time when the earth was barren with its recession. These epochs were noticed, however, not by the position of the sun at midday, but at risings and settings, or the horizon points. The two great epochs, summer and winter, were, it is believed, connected with solstitial amplitudes, and the equinoctial, horizontal points, unconnected with important times to agriculturists, were not considered as of much worth. There is every evidence, however, that the time of day was early indicated by the altitude of the sun, although the connection of the altitude at midday with the time of year was subordinated to observations on the horizon. CLASSIFICATION OF CEREMONIALS In attempting to make out the annual cycle of ceremonial observances, as determined by observations made during the last three years, I recognize two groups, the differences between which may be more or less arbitrary. These groups are called— I. The Katcinas. II. The Nine days’ ceremonials. The former of these groups, which is the subject of this article, begins with the Katcinas’ return,[15] and ends with their departure (Nimán). It is not my purpose here to do more than refer to the latter group, as a short reference to them may be of value for a proper understanding of the Katcinas. There are significant likenesses between different members of the series of nine days’ ceremonials, and they may be grouped in several pairs, of which the following may be mentioned: I. Snake or Flute.[16] II. Lálakoñti and Mamzraúti. III. Powámû and Pálülükoñti. IV. Wüwütcímti and Naácnaiya.