The climate of the Mexican highlands, which may be taken in a rough way to correspond with that of North Italy, is well suited to a nation's development.

But the cities of Yucatan and Chiapas, though geographically not far removed from the Mexican plateau, are brought by their small elevation above the sea into a very different climate.

They are in the land of tropical heat and the rankest vegetation, in the midst of dense forests where pestilential fevers and overwhelming lassitude make it almost impossible for Europeans to live, and where the Indians who still inhabit the neighbourhood of the ruined cities are the merest savages sunk in the lowest depths of lazy ignorance.
If this climate-theory of progress have any truth in it, no barbarous tribe could have raised itself in such a country to the social state which is indicated by the ruins of such temples and cities.

They must have been settlers from some more temperate region.
While wandering about the hill of Xochicalco we came upon a spot that strongly excited our curiosity.

It was simply a small paved oval space with a little altar at one end, and, lying round about it, some fragments of what seemed to have been a hideous grotesque idol of baked clay.