"The Biological Problem of To-day: Preformation Or Epigenesis? The Basis of a Theory of Organic Development, written by Oscar Hertwig and translated by Sir P. Chalmers Mitchell, offers a thought-provoking exploration of the fundamental question of biological development. Hertwig's work delves into the contrasting theories of preformation and epigenesis, shaping the foundation of our understanding of organic growth. Translated with precision, this book invites readers to contemplate the mechanisms that underlie the complexities of life."