Dilly Barlow

Conjoined twins are among the rarest of human beings. There are probably fewer than a dozen adult pairs living in the world today. Only a few hundred pairs of conjoined twins are born in the whole world each year - they appear about once in every 100,000 births - but more than half of them are stillborn, and one in three live for only a few days.

Horizon tells amazing science stories, unravels mysteries and reveals worlds you've never seen before.

Omnibus was an arts-based BBC television documentary series, broadcast mainly on BBC1 in the United Kingdom. The programme was the successor to the long-running arts-based series 'Monitor'. It ran from 1967 until 2003, usually being transmitted on Sunday evenings. During its 35-year history, the programme won 12 Bafta awards. Among the series' best remembered documentaries are Cracked Actor, a profile of David Bowie, and Rene Magritte, a graduate film by David Wheatley, 'Madonna: Behind the American dream', a film produced by Nadia Hagger, and a profile of the British film director Ridley Scott. For a season in 1982, the series was in a magazine format presented by Barry Norman. The series was replaced by 'Imagine' hosted by Alan Yentob.