Volume 3 / Book 5 — CHAPTER XVII. WHAT PART OF THE BODY IS FIRST FORMED IN THE WOMB.
Reading edition
The Stoics believe that the whole is formed at the same time. Aristotle, as the keel of a ship is first made, so the first part that is formed is the loins. Alcmaeon, the head, for that is the commanding and the principal part of the body. The physicians, the heart, in which are the veins and arteries. Some think the great toe is first formed; others affirm the navel.