Of course the prime and absolute necessity of such a study is true facsimiles; but the task of using even these, taken as they must be from much defaced inscriptions and manuscripts, is too obvious for comment. So from the very first of my studies I began to cherish thoughts of the day when Maya could be printed with type, and classified indexes to the glyphs at hand. From one point of view such facilities can only be expected to come _after_ decipherment; from another, in absence of bilingual keys, they are a necessity _before_ that can be attained. So far as his work covers, a great deal has been done in this line by Mr. A. P. Maudslay in the field of the inscriptions. At the very outset therefore I must enter acknowledgment of the assistance that I owe to the courtesy at that time of Prof. F. W. Putnam, of Peabody Museum, and Mr. Chas. P. Bowditch, in placing, with a freedom by no means universal among curators and researchers, their material at my disposal, with privilege of copying. I am safe to say that while I have reclassified the glyphs for my own use as my studies went on, yet without the copy which by Mr. Bowditch’s courtesy I was allowed to make of his card index to the glyphs of the three codices, as a start, this edition of the Perez Codex would not yet have reached daylight through the many other occupations among which Maya studies have had to take their chances. At first it seemed possible to prepare a font of separate types for the various elements of the compound glyphs we find in the texts; but after having such a font made a number of years ago, and printing a couple of pages of the Dresden Codex, the result was unsatisfactory; it became evident that the proper Maya font of type must be both separate and composite, as is used in Chinese, and not separate only as we have for Egyptian. The type for the text cards of this edition have therefore been made this way. As to the colored plates of the Codex herewith, it is evident that nothing whatever is gained by preserving the irregularities of the defaced parts of the Codex, while everything is to be gained by making all as clear and distinct as possible. The first step therefore was to have a set of photographed enlargements of two diameters, made direct from the 1864 issue. From these I made careful tracings, myself, of the black figure and glyph lines of the original, making at the same time the separate enlarged drawings from which the type were afterwards made. At this first drawing only the evident, the indisputable parts were drawn. The type forms were then classified, arranged in parallel columns, and compared. All was then gone over, and new points settled on the basis of the familiarity thus gained. It is a fair estimate to say that this process of checking and verifying was gone through, first to last, down to the final proof-reading of the printed sheets, some fifty times.