or men with jaguar masks and claws, or claws alone, also occur on stelæ at Seibal and Quirigua. [Illustration: FIG. 82.--Stone relief; Temple of the Sun, Palenque. (_After Maudslay_)] Palenque stands alone. Architecturally it is by far the most advanced of the cities of the central area, while the artistic qualities of the stucco reliefs, and the low-relief stone carvings (Figs. 49 and 52), the technique of which appears to be based on stucco-work, place them in a category by themselves. It was, in fact, only at Copan and Quirigua that the Maya showed anything like mastery over stone. The deficiency lay no doubt not so much in the artistic faculties of the mason, as in the lack of suitable tools, but it is a fact that only at the southern sites he displayed definite signs of modifying the technique borrowed from wood-carving to suit a less tractable material. Even the fine reliefs of Menché are wood-carvings translated into stone, and the same applies to the reliefs at other sites, except perhaps to the figures in niches at Piedras Negras, which in other respects noted above display a certain similarity to the Copan sculptures. When the Maya artist began to develop the art of modelling in stucco he showed that the quality of his work depended to a great extent upon the plasticity of his material, while he had gained much in technique from his experience in stone. A peculiar feature of Palenque is the comparative restraint exhibited by the artist. That he still loved complexity of detail is shown by such reliefs as Fig. 61 (p. 297), but he no longer feared the vacant space, and appreciated its value as a background. The dates on the monuments do not assist us in any way to determine the epoch which saw the rise of Palenque. The initial series in the temples give dates relating to the first cycle or even before, that is to say more than 3000 years B.C., and as such they must be regarded as purely legendary. It is impossible to believe that the site was of early foundation compared with the others. It would be against all experience to suggest that the people who built Palenque could at a subsequent period have adopted the clumsy and unnecessarily laborious architecture of Tikal. On the other hand, the site of Palenque bears a certain similarity to that of Menché, including the presence at both of buildings with underground passages and chambers, though the “palace” at Palenque is a far more elaborate construction than the analogous building at Menché, being in fact a complex of associated buildings. All the evidence seems to point to the conclusion that Palenque is the latest of the central Maya sites, and that it is most closely associated with Menché. In further proof of the latter supposition I might mention the so-called “crosses,” surmounted by birds, held by the figures in more than one of the Menché reliefs, which have their counterparts in the “crosses” of Palenque alone. The significance of these I have already discussed on p.