Contains a condensation of the author's Explicación del Códice jeroglífico de Mr. Aubin, originally published in 1889 as an appendix to Diego Duran's Historia de las Indias de Nueva España y Islas de Tierra Firme, and extracts from his Historia antigua y de la Conquista, originally published in 1888 as v. 1 of Mexico a través de los siglos, edited by Vicente Riva Palacio.
