Landa, in his "Relation of the things of Yucatan," says: "The sons or the nearest relatives succeeded to the high priest in his dignity; with him was the key of their sciences, and in that they most concerned themselves, because it was the priests who gave advice to the lords and answered their queries.... It was the high priest who nominated the priests for cities or villages which had none, examined them as to their proficiency in sciences and ceremonies. He entrusted to them the things of their office, and bade them give good example to the people. The priests employed themselves in the service of the temple and in teaching their divers sciences, particularly how to write the books that contained them. They taught the sons of the other priests and the younger sons of the princes who were sent to them in their childhood, if they saw them inclined for that profession." In order to understand the explanation of the possible origin of the mystification of the numbers 3, 5, and 7, it is necessary to know something of the people among whom it seems to have originated. If we start from the mouths of the Mississippi River and travel due south, across the Gulf of Mexico, at a distance of exactly four hundred and eighty miles, we come to the northern coast of the Yucatecan Peninsula. Its north-easternmost point, Cape Catoche, is one hundred and twenty miles from Cape San Antonio, the western end of the island of Cuba. Yucatan divides the Gulf of Mexico from the Caribbean Sea. It is comprised between the 17° 30' and 21° 50' of latitude north, and the 88° and 91° of longitude west from the Greenwich meridian. Its length is, therefore, 260 miles from north to south, and its breadth 180 miles from east to west. The whole country is a fossiliferous limestone formation, elevated a few feet only above the sea; its maximum height in the interior being about 70 feet. Although its rocky surface, bare for the most part, is, in places only, covered with a few inches of tillable loam, formed by the detritus of the stones and the decomposition of vegetable matter, its soil is of surprising fertility. The whole country is now covered with well-nigh impenetrable forests. A bird's eye view of it from the top of one of the lofty pyramids, that seem like light-houses in the midst of that ocean of foliage, impresses the beholder with the idea that he is looking on an immense sea of verdure having for boundary the horizon, and whose billows come to die, with gentle murmur, at the foot of the monument on which he stands. Not a hill, not a hillock even, breaks the monotony of the landscape, which is only relieved by clusters of palm trees that loom here and there, as islets, above the dead green level.