INTRODUCTION

At the Royal Library, there remain 43 sheets, which originally certainly formed a complete book with the others, likely written by Leonardo in 1489 original: "1489". Leonardo often dated his notebooks, providing a rare chronological anchor for his anatomical studies. ^(1).

Of these 43 sheets, five—as we shall indicate in the appropriate place—have the recto The front side of a leaf and the verso The back side of a leaf blank, and one (recto and verso) deals exclusively with the organs and functions of generation Reproduction and the reproductive system, and consequently will form part of Leonardo’s book on generation, also belonging to the Royal Library at Windsor.

The original pages that we are now publishing therefore number 79, and they contain, along with the text, 193 figures.

We provide the heliotype An early photographic process used for high-quality reproductions of manuscripts reproduction of these pages, in the size of the original, and in the order which, according to several minutely studied clues, almost always coincides with that established by Leonardo.

We must note in this regard that some sheets are marked with ancient letters, and others by ancient and modern numbers—marks reported by us, for the sake of precision, within square brackets, because they are not in Leonardo’s hand; however, they do not serve as a guide for the layout.

The diplomatic transcription A precise transcription that preserves the original spelling, punctuation, and layout exactly as written then provides, as we have said before, with the greatest accuracy, everything contained in the original manuscript; it is, in substance, nothing but a second reproduction of the manuscript in typographic characters accessible to all ^(2).

To this transcription corresponds the explanatory critique, which scrupulously preserves the integrity of the text, changing only a few incidentals, the modification of which is indispensable to make it entirely intelligible.

The first transcription makes the text readable, the second makes it understandable ^(3).

To these two transcriptions corresponds the English translation original: "traduction française". This refers to the French translation provided in the source volume this text introduces., to bring the manifestations of Leonardo's genius within reach of the greatest number of people.

(1) Sheet 42 recto, page 251 "This day, the 2nd of April 1489, book entitled 'On the Human Figure'." original: "Ce jour 2 d'avril 1489, livre intitulé de la figure humaine". This is a crucial citation where Leonardo explicitly names his project.
(2, 3) Codex on the Flight of Birds, published by Th. Sabachnikoff. Transcriptions and notes by G. Piumati, pages 40-42.