Leonardo da Vinci and the origin of semen

Abstract

It is well known that Leonardo da Vinci made several drawings of the human male anatomy. The early drawings (before 1500) were incorrect in identifying the origin of semen, where he followed accepted teaching of his time. It is widely thought that he did not correct this mistake, a view that is reflected in several biographies. In fact, he made a later drawing (after 1500) in which the description of the anatomy is remarkably accurate and must have been based on careful dissection. In addition to highlighting this fact, acknowledged previously in only one other source, this article reviews the background to Leonardo's knowledge of the relevant anatomy.

Bodily Fluids in Antiquity

“…In the famous image from Leonardo da Vinci, created before he dissected any complete human cadavers, an imagined male and female body meet in generation (Royal Collection Trust, RL 19097v). Noble et al (2014) argue that in 1508 Leonardo corrected his views and removed the connection seen in this image between the spinal cord and the channels carrying the seed. 1 Leonardo's hemisected man, his spine clearly visible and linked to his seed production, recalls the Hippocratic On Airs, Waters, and Places (22) description of the Scythians, who cut the channels behind the ears and thus prevent their semen from moving properly down the body; in the male body, the head and the spine are thus also considered relevant to generation.…”