"Degeneration: A Chapter in Darwinism" is a book written by E. Ray Lancaster, an eminent English biologist and director of the London Natural History Museum. The publication is one of the most influential works in the field of science and literature of the end of the 19th century. In this book, the author examines the concept of degeneration in the context of Darwinism and reflects the consequences of this phenomenon for people and society as a whole. Transformation is highlighted by Lankester as a complex process that can have both positive and negative consequences. The author examines various aspects of degeneration - from physiological to social, inviting the reader to rethink traditional ideas about the biological product of evolution. Through a passionate style and in-depth analysis, Lancaster uncovers important questions that remain relevant today.