Without committing himself to a theory, M. de Bourbourg supposes that one race—­the Quiche—­has passed through the whole North American continent, erecting at different stages of its civilization those gigantic and mysterious pyramids, the tumuli of the Mississippi Valley,—­of whose origin the present Northern Indian tribes have preserved no trace, and for whose erection no single American tribe now would have the wealth or the superfluous labor.  This race was continually driven towards the South by more savage tribes, and it at length reached its favorite seats and the height of its civilization in Central America.  In comparing the similar monuments of Southern Siberia, and the dates of the immigration to the Aztec plateau, with those of the first movements of the Huns and the great revolutions in Asia, an indication is given, worthy of being followed up by the ethnologist, of the Asiatic origin of the Central American tribes.  The traditions, monuments, customs, mythology, and astronomic systems all point to a similar source.

The thorough study of the aboriginal races reveals the fact, that the whole continent, from the Arctic regions to the Southern Pole, was divided irregularly between two distinct families;—­one nomadic and savage, the other agricultural and semi-civilized; one with no institutions or polity or organized religion, the other with regular forms of government and hierarchical and religious systems.  Though differing so widely, and little associated with each other, they possessed an analogous physical constitution, analogous customs, idioms, and grammatical forms, many of which were entirely different from those of the Old World.

At the period of the discovery of America, not a single tribe west of the Rocky Mountains possessed the least agricultural skill.  Whether the superiority of the Central American and Mexican tribes was due to more favorable circumstances and a more genial climate, or to the instructions of foreign legislators, as their traditions relate, our author does not decide.  In his view, American agriculture originated in Central America, and was not one of the sciences brought over by the tribes who first emigrated from Asia.

Of the architectural ruins found in Central America M. de Bourbourg says:  “Among the edifices forgotten by Time in the forests of Mexico and Central America are found architectural characteristics so different from one another, that it is as impossible to attribute their construction to one and the same people, as it is to suppose that they were built at the same epoch....  The ruins that are the most ancient and that have the most resemblance to one another are those which have been discovered in the country of the Lacandous, the foundations of the city of Mayapan, some buildings of Tulha, and the greater part of those of Palenque; it is probable that they belong to the first period of American civilization.”—­Vol.  I. p. 85.