Coitus

   This hemisection of a copulating couple is perhaps Leonardo's most unusual anatomical drawing.  It shows a tube by which semen was thought to pass from the brain through a channel in the spine - one of the ideas current at the time and accepted by Leonardo.

"The penis does not obey the order of its master," wrote Leonardo, "and must be said to have its own mind."

Female Anatomy

   Again the influence of the anatomical knowledge of the time is seen in this drawing of a disected woman.  The heart is shown as having two chambers instead of four and the vagina has the form of an inverted penis.

Discoveries

   Leonardo made several remarkable anatomical discoveries during his examination of some thirty corpses.  He was the first to draw correct representations of the curves of the spine, the tilt of the sacrum, the arches of the ribcage and the exact position of the pelvis.

Leonardo explored the bones of the face and skull in detail and explored cavities such as the maxillary cavity.  The drawing shows Leonardo's use of different types of shading to give the impression of layers in three dimensions.