title: Letter to the editor.
authors.forename: Frank
authors.initials: F
authors.lastname: Stahl
authors.forename: Matt
authors.initials: M
authors.lastname: Meselson
mesh_terms: D002876:Chromosomes, Bacterial / Q000737:chemistry* / Q000235:genetics; D004261:DNA Replication; D004269:DNA, Bacterial / Q000737:chemistry*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D009690:Nucleic Acid Conformation
chemical_list: D004269:DNA, Bacterial