Negras are connected with temples. At Copan and Quirigua some appear to be independent. They are usually found situated in the courts, though at Piedras Negras a series exists arranged along the lower terrace of a foundation-mound. Many are furnished with altars in front of them (Fig. 81), and they appear to have been the objects of some cult. A most important point in connection with them lies in the fact that so many of them bear dates in the long count as described in chapter X, and this fact, combined with the statements of early authors that the historical Maya were wont to mark the
passage of a katun by setting up a "stone," lends colour to the opinion that the early Maya followed a similar practice. Many of the dates mark quarter katuns, but many again do not, and though we may conclude that they were in some way commemorative monuments, it is impossible at present to define their use more exactly. As stated before, many of the stelæ were painted in colours, and plain stelæ occur at Tikal and elsewhere, which probably once bore some painted design. The evident relation which Maya sculpture bears to woodcarving renders it probable that many wooden stelæ may once have existed, especially in the earliest times. It is worth noting that at Copan the stone foundations which support the stelæ enclose small cruciform vaults,
