bad usage in a wonderful manner. Inside this casing were adobes, stones, clay, and mortar, as one may see in places where the exterior has been damaged, and by creeping into the small passage which leads into the Temple of the Moon. Both pyramids are nearly covered with a coating of debris, full of bits of obsidian arrows and knives, and broken pottery. On the teocalli of the moon we found a number of recent sea-shells, which mystified us extremely; and the only explanation we could give of their presence there was that they might have been brought up as offerings. A passage in Humboldt, which I met with long after, seems to clear up the mystery. Speaking of the great teocalli of the city of Mexico, he says, quoting an old description, that the Moon had a little temple in the great courtyard, which was built of shells. Those that we found may be the remains of a similar structure on the top of the pyramid.
Prickly pears, aloes, and mesquite bushes have overgrown the pyramids in all directions, as though they had been mere natural hills. In Sicily one may see the lava fields of Etna planted with prickly pears: in the ordinary course of things, it requires several centuries