|Human Fetus drawn by Leonardo da Vinci|
A similar debate 50 years ago was initiated by James Dixon Boyd and William James Hamilton in connection with the first edition of their influential textbook Human Embryology (previous post). This was in the BMJ. Coincidentally Bernard Towers (later Professor of Anatomy and Pediatrics at UCLA) raised the issue in Arch Dis Child. Earlier, Lionel Everard Napier had argued for "fetus" in The Lancet.
The thrust of their arguments was that "fetus" was the only spelling in use until 600 A.D., "foetus" being introduced by Isidorus of Seville on the basis of an erroneous etymology.
|Statue of Isidorus of Seville in Madrid|
Photo by Luis Garcia CC BY-SA 2.5
References: BMJ 1967 (5337): 425, (5539): 568, (5540): 631, Arch Dis Child 1967; 42:224, Lancet 1952; 260: 885-6.