The book "On the Study of Zoology" was written by the outstanding English scientist Thomas Henry Huxley. In this work, the author explores the vast world of animals and their relationships in the natural environment. In particular, he examines in detail the structure and functions of various species of animals, describes their behavior, methods of nutrition and reproduction. In addition, Huxley considers the evolutionary aspect of zoology, separating the basic laws of natural selection and adaptation in living organisms. This book has become a significant contribution to the development of zoological science and will arouse the interest of everyone who is interested in the amazing forms of life on the planet.