Leonardo’s study of the human body led him to investigate the phenomenon of reproduction.

Leonardo had access through dissection to a human foetus of approximately seven months, which he represented in a group of surviving drawings from various viewpoints. Here in the main drawing, the uterus and embryonic membranes are shown bursting magically open like the coverings of a germinating bud to reveal a foetus in the breech position. The umbilical cord is shown coiled in a serpentine line. The cotyledons of the placenta are observed from the uterus of a cow, and are added to the human foetus to produce as comprehensive an image as possible of the reproductive system.