GEGENBAUR, KARL (1826—). A German comparative anatomist. He was born in Wilrz burg, Germany, and studied medicine in Wttrz burg, where he was a pupil of KiiHiker and of Virchow; received the degree of M.D., and was afterwards privat-docent from 1853 to 1855. In the latter year he became professor of anatomy and director of the Anatomical Institute in Jena, and remained there until 1873, when he became professor of anatomy at Heidelberg. He spent two years in Sicily studying invertebrate life, making important researches on pteropods and heteropod mollusks. He also worked on the his tology of Limulus. He is not only the leading comparative anatomist in Germany, but one of the first class, ranking with Huxley and Owen, and is distinguished by the great range of his learn ing, which covers the entire field of animal mor phology, as well as by the boldness of his specu lations. He was the first comparative anatomist to place the study of anatomy on an evolutionary basis, and thus became the founder of modern anatomy. His most important works are: Grundziige der vergleichenden Anatomic. (1870) ; Grundriss der vergleichenden Anatomic (1878), translated into English by F. J. Bell, under the
title Elements of Comparative Anatomy (1878) ; Lehrbuch der Anatomic des Menschen (1883; 3d ed. 1886) ; Vergleichende Anatomic der Wirbel thiere mit Beriicksichtigung der Wirbellosen (1898). Since 1876 he has edited the Morph°lo gisches Jahrbuch, which he founded. In his Com parative Anatomy of Vertebrates (1898) Gegen baur shows how conditions prevailing among invertebrates can be made to throw light upon the more complicated vertebrate forms. Gadow char acterizes this great work as "a mine of most suggestive ideas." In this, as in all his works, he strives to derive any given organ from some earlier, more ancestral or generalized structure, instead of being satisfied with its conditions or its present degree of specialization. Gegen baur's most fruitful work was his theory of the origin of limbs and their girdles from the embry onic visceral arches. His views on the derivation and evolution of free limbs were also the outcome of a masterly research.