title: Zentralblatt für Bakteriologie--100 years ago: protozoa as causative agents of smallpox, or: Cytoryctes and no end.
authors.affiliation: Friedrich-Schiller-Universität, Institut für Experimentelle Mikrobiologie, Jena, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Köhler
mesh_terms: D000818:Animals; D056890:Eukaryota / Q000302:isolation & purification*; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D012899:Smallpox / Q000266:history* / Q000469:parasitology; D014615:Vaccinia / Q000266:history* / Q000469:parasitology