Agassiz, LOUIS JOHN RUDOLPH (1807-1873), an eminent naturalist, son of a Swiss Protestant clergyman. He completed his education at Lausanne, and early developed a love of the natural sciences. He studied medicine at Zurich, Heidelberg and Munich. His attention was first specially directed to the study of fishes by being called on to describe the Brazilian fishes. As professor of natural history at Neuchatel he distinguished himself by his discoveries concerning fossil fishes. His researches led him to propose a new classification of fishes, which he divided into four classes, distinguished by the characters of the skin. His system has not been generally adopted, but the names of his classes have been used. In 1836 he began the study of glaciers. In 1838 he was induced to settle in America, where he was connected as a teacher first with Harvard University, Cambridge, and later with both Cornell University and Harvard. He engaged in various investigations and explorations and published numerous works. In 1865 he made zoological excursions and investigations in Brazil, which were productive of most valuable results. Agassiz held views on many important points in science different from those which prevailed among the scientific men of the day, and in particular he opposed the theory of evolution. His most important writings are Researches on Fossil Fishes, Glacial Systems, Outlines of Comparative Physiology and A Journey to Brazil.