As this discussion is preliminary to a discussion of the assignment of the symbols of the cardinal points, it becomes necessary, in order to bring in all the evidence bearing upon the question, to examine certain points of the Mexican calendar system, as given by various authors and as exhibited in the Mexican Codices. If we refer now to Plate 43 of the Borgian Codex, as found in Kingsborough's "Mexican Antiquities," Vol. III, a photo-engraved copy of which is presented in our Fig. 4, we shall, as I believe, not only find additional confirmation of the views I have advanced in reference to the peculiar arrangement of the days around the quadrilateral in the plate of the Cortesian Codex, but also strong evidence of a common origin of the Mexican and Central American calendars. [Illustration: FIG. 4.--Copy of plate 43. Borgian Codex.] This plate of the Borgian Codex, which is Mexican and not Maya, consists of four groups, the whole arranged in the form of a square; each group, also a square, is surrounded by a serpent, the heads of the four serpents being brought near together at the center, which is indicated by the figure of the sun. Each of these serpents, as I have heretofore intimated,[9] probably denotes one of the four-year series of the cycle of fifty-two years, just as in the Maya cycle we would say "the Cauac series," "Kan series," etc.[10] The thirteen years of each series, is denoted by the small circles on the serpents. The four large figures are, as we shall hereafter see, fanciful representations of certain ideas held by this people in regard to the four cardinal points, each probably with its significant color as understood by the artist, and each probably indicating one of the four-year bearers. But at present our attention is directed to something else to be found on this plate. In each of the four spaces and around each of the large figures we observe five Mexican day symbols connected usually with the main figure by heavy-waved colored lines. What is the signification of these day symbols in this connection? Precisely the same, I believe, as those in the four sides of the quadrilateral in the Codex Cortesianus. But first I would remark that the waved, colored, connecting lines have no other signification than to denote the parts of the body to which the days are here severally assigned; hence, as they have no bearing on the questions now under discussion, I shall have no occasion to take any further notice of them. If we arrange the Mexican days in four columns as we did the Maya, that is, placing the first name in the first column, the second in the second column, and so on, following the usual orthography and the order given, the groups will be as follows: TABLE XI.