(COMBO) This combination of file pictures created on September 14, 2016 shows the logo of German pharmaceutical giant Bayer (top, on July 24, 2013 in Berlin) and a banner on a building on the campus of Monsanto Headquarters (on May 23, 2016 in St Louis, Missouri). German chemicals giant Bayer said on September 14, 2016 it had signed a $66 billion (58.8 billion euros) takeover deal with US genetically modified (GM) seeds firm Monsanto. / AFP PHOTO / Michael B. Thomas AND John MACDOUGALL