The book "Reflections: Biological and Geological Essays" was written by the outstanding British naturalist Thomas Henry Huxley. In this work, the author explores various aspects of biology and geology, highlighting the relationship between these two branches of natural sciences. The collection of essays offers the reader a deeper understanding of the nature of the world around us through the prism of biological and geological facts, which the author explains from his own scientific vision. "Reflections: Biological and Geological Essays" is considered a classic work of natural science literature, which leaves an important mark in the development of scientific knowledge about the world of plants, animals, geological structure and evolutionary processes.