Part one of Da Vinci’s ”Studies of the Fetus in the Womb”, ca. 1511, which correctly depicts a human fetus in a breech position inside a dissected uterus.
Views of a Fetus in the Womb
Design for a giant crossbow by Leonardo da Vinci.
Geometries by Leonardo da Vinci
Sketches and notes by Da Vinci describing how by pouring hot wax into an ox’s heart, making a mould of thin glass from the cast, and then pumping water mixed with seeds through it, he deduced the essential role of the vortices in the sinus of Valsalva in the closing of the aortic valve