This volume of reviews revises and up-dates those sections of Charles Darwin's monographs that deal with the general biology of barnacles; how they live, behave, grow and breed. Each chapter reviews the new work, but places it in the context of Darwin's original observations, and assesses how Darwin's conclusions are affected by recent discoveries and ideas. Chapter headings: 1. Evolution and genetics. 2. Physiology and function. 3. Larval biology and settlement. 4. Pollution and fouling.