Siebold (zē´bôlt), family of German scientists. It includes Karl Kaspar von Siebold (kärl käs´pär fən), 1736–1807, anatomist and surgeon, who was professor at the Univ. of Würzburg from 1769. He was ennobled in 1801. A son, Adam Elias von Siebold (ä´däm ālē´äs), 1775–1828, was noted as an obstetrician. He taught at the universities of Würzburg (1799–1816) and Berlin (from 1816), where he founded a noted obstetrical clinic. Phillip Franz van Siebold was his son. Eduard Kaspar von Siebold (ā´dōōärt), 1801–61, another son, was also a noted obstetrician. He was professor at the universities of Marburg (1829–33) and Göttingen (from 1833). A third son, Karl Theodor Ernst von Siebold (tā´ōdōr ĕrnst), 1804–85, also a physician, was one of the foremost biologists of his time. He specialized in the comparative anatomy of invertebrates and wrote the first volume (1846) of Lehrbuch der vergleichenden Anatomie; this volume appeared in English under the title Anatomy of the Invertebrata (1854). Especially noteworthy are his research on intestinal parasites and his work on the classification of invertebrates. He taught from 1853 at the Univ. of Munich.