This week's programme in the series on Man and Science today.

"I would just remind you of the basic time scale. It is four births and two deaths every second" (Dr. R. Boote, Deputy Director, Nature Conservancy)

Last month the Nature Conservancy had its 21st birthday. As the crisis in the environment increases - with threats from pollution and pesticides, or just too many people-their work as guardians of our countryside becomes more and more significant. Tonight's film is about their work, ranging from the dramatic way in which they saved the birds of prey from extinction to their painstaking research into the value of hedgerows, fast disappearing under pressure of modern agriculture.
Most of the Conservancy's work is complicated and intricate, and it is still a small institution. Yet their work is vital if we want to preserve anything of our countryside for the future.