Leeuwenhoek meets Kussmaul: the evolution of endoscopist to endo-pathologist.
D020776:Endoscopes, Gastrointestinal / Q000266:history*; D016099:Endoscopy, Gastrointestinal / Q000266:history*; D005762:Gastroenterology / Q000266:history*; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D008853:Microscopy / Q000266:history*