When Leonardo da Vinci died (May 2, 1519) his anatomic notes and sketches passed by will to his faithful friend Melzi who, while he lived, guarded them as his most precious possessions; but unfortunately this reverence did not pass with them to his heirs. Yet, notwithstanding their extensive, roundabout, and still in large degree untracked travels, a very large part of Leonardo's anatomic manuscripts and drawings at last found safe abodes and became available for study and reproduction under favorable conditions.1 How much has been lost will never be known. The quadricentennial anniversary of Leonardo's death has brought out a number of articles2 in which his work, particularly in anatomy and physiology, is discussed in the light of the latest investigations that anatomists, historians and linguists have made of it.
It appears to be established beyond any question of doubt that Leonardo commenced to dissect when he was