1.后成论与先成论的持久论争 History Epigenesis vs Preformation Preformation: Everything in the embryo is ' pre-formed and simply grows during development. Epigenesis: New structures arise progressively during development (homunculus)within Malpighi's drawings of sperm(1694) chick embryos(1673) 5th century BC: Aristotle favored epigenesis 17th century Marcello Malpighi Chick embryology description(s) should have confirmed aristotles ideas Preformation regained popularity1. 后成论与先成论的持久论争