Lorenz Okey, a German naturalist, born at Bohlsbach, Wtirtemberg, Aug. 1, 1779, died in Zurich, Aug. 11, 1851. His real name was Lorenz Ockenfuss, which he abridged to Oken when he became a private teacher at Gottin-gen. He had studied natural history and medicine at the university of Wiirzburg. In his Orundriss der Natiirphilosophie (8vo, 1802) he maintained that animal classes are simply a representation of the organs of sense, and divided the animal kingdom accordingly into five classes. In Die Zengung (1805) he advanced the doctrine that all organic beings originate from and consist of vesicles or cells. In his Beitragezurvergleichendeu Zoologie, Anatomic und Physiologie (1806) he demonstrated that the intestines originate from the umbilical vesicle, and that this corresponds to the vitellus or yolk bag; in the same work he described the corpora Wolffiana or primordial kidneys. In 1807 he became extraordinary professor of the medical sciences at Jena, his celebrated inaugural discourse, Ueber die Bedeutung der Scliadelhiochen, being delivered in the presence of Goethe, who as rector of the university had invited him thither, and from whom he has been unjustly accused of borrowing his vertebral theory of the skull.

The first edition of his Lehrbuch der Naturphilosophie was published in 1808-'ll, a second in 1831, and a third in 1843; the last was translated into English by Dr. Tulk (London, published by the Ray society, 1847). In 1810 he was made court councillor, and in 1812 ordinary professor of natural sciences at Jena. In 1816 he commenced the publication of his celebrated periodical, the Isis, devoted principally to natural science. His political criticisms led the court of Weimar to require him either to suppress the Isis or to resign his professorship; he chose the latter alternative, and published his journal (prohibited at Weimar) at Rudolstadt uninterruptedly till 1848. Accused in 1819 of being a member of a forbidden secret democratic society, he was tried and acquitted, and thereupon retired to private life. In 1828 he resumed his occupation of private teacher in the newly established university at Munich, and soon after was appointed professor there. In 1832, on the proposition of the Bavarian government to transfer him to a provincial university, he resigned his appointments, went to Switzerland, and in 1833 was appointed professor of natural history in the university of Zurich, which post he retained until his death.

A statue has been erected in his honor in the university of Jena. His views on philosophical anatomy will be found under that title.