In the library of the Peabody Museum of Harvard University there is an invaluable collection of photographs of old manuscripts relating to Middle America. These photographs, made by Professor William E. Gates of Point Loma, California, were given to the Peabody Museum by Charles P. Bowditch, Esq. , of Boston. One of the volumes contains a photographic reproduction of an original manuscript entitledRelación de las dos Entradas que hizé a Peten Ytza. The author, Fray Andrés de Avendaño y Loyola, of the Order of Saint Francis, will receive much of our attention later. Fortunately Mr. Bowditch and Sr. Guillermo Rivera have deciphered and translated the crabbed old text, so that we have at hand an account of the subjection of the Itzas of Tayasal, or Peten Itza, which is not only invaluable as being the work of an eyewitness of that subjection, but which also is filled with a rare charm. It was largely with a view to bringing this old manuscript to the attention of students that Mr. Bowditch and Dr. Tozzer asked me to work it up into a study of the Itzas of Tayasal. At the same time we must not neglect to notice here the translation, made by Mr. Bowditch and Sr. Rivera, of another inedited work on the same subject. I refer to the account by Fray Alonso Cano, which will be of great use to us later.