STAGE

A Lasting ‘Mousetrap’: “The Mousetrap,” the world’s longest-running play, reached its 40th birthday in London this week, and the daily trickle of tourists at the box office bodes well for the continued survival of the Agatha Christie play-turned-institution. Put together with $20,000, “The Mousetrap” has grossed more than $45 million. The original star, Richard Attenborough, went on to become an Oscar-winning film director, but few big names have been part of it since. Tiny changes have been made over the years. Wireless is now radio. Drugs have replaced a cache of stolen Swiss watches. And the textual emphasis on smoking has been abolished in keeping with more health-conscious times.