On reading Señor Lera’s valuable contribution I found evidences that he was unacquainted with the scholarly monograph privately published in Mexico in 1879, by the distinguished scholar and diplomat, Señor Ortega, under the title “Historical Note on the Political and Commercial Relations Between Mexico and Japan in the XVIIth Century.” I found moreover that although Señor Lera refers to it, neither of the above writers had ever read that most valuable document, the detailed report of his embassy submitted to Viceroy Mendoza, by the first ambassador ever sent from New Spain to Japan. This is contained in Vol. VIII of that monumental work published in Madrid: Collection of unedited documents relating to the discovery and conquest and organization of ancient Spanish possessions in America and Oceania. Finding myself deeply interested in the facts preserved in the above disconnected monographs, it occurred to me that I could not send to the San Francisco meeting of the Anthropological Association a more acceptable communication than a compilation of all three publications, with translations of the original documents contained therein. In preparing this I found it necessary, in order to fill certain gaps, to refer to a number of works on Japan, and also to incorporate certain data contained in a newspaper article recently published in the City of Mexico by the erudite Father V. de P. Andrade. I venture to believe that the data collectively presented here, for the first time in English, will be of interest and value, not only to historians and ethnologists, but also to the general public. To them it will doubtless be a matter of surprise, as it was to me, to learn that it was no less a personage than Tokugawa Iyeyasu, surnamed “The Illustrious,” who, in 1598, took the first steps towards establishing official relations with Mexico. Iyeyasu is known to have inaugurated the policy of exclusion and isolation, which was perfected by his grandson, Iyemitsu, and to have organized the form of government which secured to Japan a peace of two hundred years.