David Attenborough. Carl Sagan. Richard Dawkins. Michael Faraday. Alice Roberts. These are only a few of the many notable scientists who have given the Christmas Lectures. You can watch many of the past series at: http://www.rigb.org/christmas-lectures/watch But five whole series and a single David Attenborough episode are missing. We need your help to try to find them. To find out which lectures are missing and how you can help, please visit: http://www.rigb.org/christmas-lectures/missing-lectures #missingxmaslectures