(b. 1452, Vinci, d. 1519, Cloux, near Amboise)

Studies of embryos

Black and red chalk, pen and ink wash on paper, 305 x 220 mm
Royal Library, Windsor

The sheet includes studies from a number of years. The note "book on water to Mr. Marcho Ant" refers to the anatomical expert Marcantonio della Torre, who died in Pisa in 1511 and with whom Leonardo carried out dissections of human bodies. This drawing of the fetus was the result of knowledge rather than direct observation of nature. Leonardo had examined the fetus of a cow and allowed his observations of the placenta to influence this drawing.