title: The development of the virus concept as reflected  in corpora of studies on individual pathogens. 2. The agent of fowl plague--a model virus.
mesh_terms: D000818:Animals; D002642:Chick Embryo; D049672:History, 19th Century; D049673:History, 20th Century; D009980:Influenza A virus; D014773:Virology / Q000266:history*; D014780:Viruses