born Aug. 25, 1793, Danzig, Prussia
died Sept. 3, 1860, Königsberg
German anatomist and embryologist.
He was the first to describe gill slits and gill arches in mammal and bird embryos. He thought they were vestigial gills but recognized their significance in development of the associated blood vessels. He first described the Rathke pouch (1839), an embryonic structure that develops into the pituitary gland's anterior lobe. He also did pioneering marine zoology research.