Originally published in Quaderni D'anatomia. Vol. III. Fogli della Royal Library di Windsor, Organi della Generazione, Embrione. C.L. Vangensten, A.M. Fonahn and H. Hopstock, editors. Christiania, J. Dybwad, 1913. ca. 1510-1512.Photo of the original from the Royal Library, Windsor. Originally drawn while Leonardo was an assistant to Marcantonio Della Torre, Professor of Anatomy at the Univrsity of Pavia. Fetus in the breech position, with the fetal membranes and umbilical cord. Although Leonardo correctly depicts the single placental disc (upon which the fetus is sitting; the coiling umbilical cord can be seen just under the placental disc), he mistakenly depicted the placental attachment as cotyledonary (he clearly depicts the fetal cotyledons interdigitating with the maternal crypts in the upper right portion of drawing). In fact, this cotyledonary or “placentomal” arrangement exists only in ruminants (antelope, cattle, deer, giraffes, goats, and sheep).These images were taken while preparing a book (Wombs with a View, Springer, 2016) on the history of the illustrations and how they contributed to our understanding of anatomy and physiology of pregnancy, thereby enabling advances in the practice of obstetrics and gynecology.