Karl Gustav Carls, a German physician and naturalist, born in Leipsic, Jan. 3, 1789, died in Dresden, July 28, 1869. After studying in the gymnasium and university of his native place, he devoted himself to chemistry, in order to aid his father, who was a dyer. He soon left chemistry, and in 1811 graduated at Leipsic as a physician. Engaged as teacher in the university, he was the first to deliver there a distinct course of lectures on comparative anatomy. In 1813 he was appointed to the French hospital at Pfaffendorf, near Leipsic, and by his devotion to his patients contracted a severe illness. The following year, on the reorganization of the medico-chirurgical academy of Dresden, he was appointed professor of midwifery, and at the same time had the clinical direction of the lying-in hospital. In 1827 he resigned his professorship on being appointed physician to the king of Saxony. He continued, however, to lecture, and in 1827 delivered a course of lectures on anthropology, and in 1829 on psychology, which added greatly to his previous reputation. Besides his professional and scientific labors, Carus was a painter of marked talent.

His reputation rests mainly on his discovery of the circulation of the blood in insects, for which he received a prize from the French academy of sciences, and his contributions to the history of development in animals. His principal works are: Versuch einer Darstellung des Nrervensystems, und inbesondere des GeJiims (Leipsic, 1814); Lehrbuch der Zootomie, with 20 plates engraved by himself (1818); Erlauterungstafeln zur ver-gleichcndenAnatomie (3 vols., 1826-'35); Ueber den Blutkreislauf der Insecten (1827); Grund-zi'ige der vergleichenden Anatomie und Physio-logie (3 vols., Dresden, 1828); Vorlesungen uber Psychologic (Leipsic, 1831); Briefeaber Land-schaftsmalerei (1831); Symbolik der menscJi-lichen Gestalt (1852); Erfahrungsresultate aus artelichen Studien und artzlichem Wirlcen wdh-rend cines halben Jahrhunderts (1859); Natur und Idee, oder das Werdende und sein Gesetz (Vienna, 1861); and Lebenserinnerungen und Denkwurdigkeiten (4 vols., Leipsic, 1865-'6).