The Biological Problem of To-day: Preformation Or Epigenesis? The Basis of a Theory of Organic Development

"The Biological Problem of To-day: Preformation Or Epigenesis?" by Oscar Hertwig is a scientific exploration of how living things grow and change. It looks at two main ideas: preformation, the concept that everything is already there in a tiny package from the start, and epigenesis, the idea that things build up step by step. Written in the style of late 19th-century scientific writing, the book's opening introduces the big question of whether things are pre-set or if development is a more gradual process. It talks about other scientists' ideas, especially a biologist named August Weismann, and his theory about germplasm. The author examines the subject to show that actual development is more like epigenesis, where living things grow through the world around them, instead of just unfolding something that was pre-planned. The launch of the book starts a more examined quest that looks at what these ideas mean for learning about heredity and existence.