Siebold, Carl Theodor Ernst Von

Born Feb. 16, 1804, in Würzburg; died Apr. 7, 1885, in Munich. German zoologist. Professor at the universities of Erlangen (from 1840), Freiburg (from 1845), Breslau (from 1850), and Munich (from 1853).

Siebold distinguished protozoans as a special phylum, Protozoa, which he divided into two classes, Infusoria and Rhizopoda. He founded the phyla of worms (Vermes) and arthropods (Arthropoda). He established that parasitic worms are not generated spontaneously in the host’s intestine but develop from ova and showed the entrance paths of many of them into the intestine; he was the first to describe the succession of hosts in a number of parasitic worms. He was the author of several works on parthenogenesis in arthropods. After the publication of Darwin’s The Origin of Species in 1859, he became an advocate of the idea of evolution of living nature. In 1848, together with R. Kölliker, he founded the journal Zeitschrift für wissenschaftliche Zoologie, which exists to this day.