The perfect execution of the details in the bas-reliefs and the accuracy with which they are repeated show clearly that it was not so much want of skill as the necessity of keeping to the conventional mode of representing objects that has given so grotesque a character to the Mexican scriptures. Certain figures became associated with religion and astrology in Mexico, as in many other countries; and the sculptor, though his facility in details shows that he could have made far better figures if he had had a chance, never had the opportunity, for he was not allowed to depart from the original rude type of the sacred object. Humboldt remarks that the same undeviating reproduction of fixed models is as striking in the Mexican sculptures done since the Conquest. The clumsy outlines of the rude figures of saints brought from Europe in the 16th century were adopted as models by the native sculptors, and have lasted without change to this day. It is evident that Xochicalco answered several purposes. It was a fortified hill of great strength, also a sacred shrine, and a burial-place for men of note, whose bodies, no doubt, still lie under the ruined cairns near the pyramid. The magnitude of the ditch and the terraces, as well as the great size of the blocks of stone brought up the hill without the aid of beasts of burden, indicate a large population and a despotic government. The beauty of the masonry and sculpture show that the people who erected this monument had made no small progress in the arts. We must remember, too, that they had no iron, but laboriously cut and polished the hardest granite and porphyry with instruments of stone and bronze; we can hardly tell how. The resemblances which people find between Assyrian and Egyptian sculptures and the American monuments are of little value, and do not seem sufficient to ground any argument upon. When slightly civilized races copy men, trees, and animals in their rude way, it would be hard if there were not some resemblance among the figures they produce. With reference to their ornamentation, it is true that what is called the “key-border” is quite common in Mexico and Yucatan, and that on this very pyramid the panels are divided by a twisted border, which would not be noticed as peculiar in a “renaissance” building. But the model of this border may have been suggested—on either side of the globe—by creepers twined together in the forest, or by a cord doubled and twisted, such as is represented in one of the commonest Egyptian hieroglyphs.