Born June 18, 1855, in Oftringen, Aargau; died Nov. 30, 1914, in Zürich. Swiss zoologist and specialist in the comparative anatomy of invertebrates.
Lang was a student of E. Haeckel. From 1878 to 1885 he studied various groups of marine invertebrates at a zoological station in Naples. In 1889 he became a professor at the University of Zürich. His principal works were on the comparative anatomy and phylogeny of worms. He was the author of a theory of the origin of turbellarians from Ctenophora and of annelids from Platyhelminthes. He also developed a hypothesis on the origin of the coelom and the circulatory system. A number of Lang’s works dealt with the influence of sessile life on the origin of asexual reproduction.
WORKSÜ ber den Einfluss der festsitzenden Lebensweise auf die Tiere undü ber den Ursprung der Ungeschlechtlichen Fortpflanzung durch Teilung und Knospung Jena, 1888.
Lehrbuch der vergleichenden Anatomie der Wirbellosen Thiere. Jena, 1888–94.