The objects which he found, and the depth at which he found them, only went further to prove that his conclusions were correct. Bones of animals which had served as food, charcoal, and potsherds, with earth of sometimes a foot deep between the layers, went to show that the cave was inhabited and evacuated, and then left for some years before it was again occupied. From the fact that horses' teeth were found in many of them, but always of course in the topmost layers, it may be assumed that the caves were in use (perhaps only when a rout was taking place) after the arrival of the Spaniards. But the fact that none of the potsherds discovered in the caves are like those usually found among the ruins, and especially the fact that no vases with hieroglyphics on them are found, go to show that the caves in Yucatan were but little in use, if at all, among the building Mayans. From all this it would seem safe to conclude that if these caves were ever permanent habitations, it was at a period anterior to the great building age of the Mayan race, when their civilisation was in the crude stage to which many of the North Americans had attained. This conclusion is certainly supported by the fact above referred to, that the coarse carvings at Opichen are almost facsimiles of those of the pictographs of the Northern tribes. Thus everything would seem to point to the conclusion that, whoever these Mayan builders were, their knowledge of architecture was not slowly evolved by them, but came to them, a veritable gift of the gods, already developed, from some foreign source. What that source was we shall endeavour to show in the next chapter. The point to be dealt with here is, What were the ethnical affinities of the Mayans themselves? To what branch of the great American family do they belong? We have endeavoured to show that the mysterious disappearance of the Toltecs and the traditionary account of their flight south point very clearly to the conclusion that the country south of Mexico was at the arrival of the Aztecs inhabited by the kindred of these so-called Toltecs.