Correction.
In Jean L. Marx's briefing "Bar Harbor investigation reveals no fraud" (News and Comment, 17 June, p. 1254), the report of the investigating committee was incorrectly quoted to have said that Hoppe "cannot rule out the possibility that the embryos were switched before implantation." What the report actually says is, "Nevertheless, he [Hoppe] could not rule out the possibility that deliberate switching of young mice in experimental litters took place."