Centuries ago, people in warmer parts of the earth believed that a dread disease was contracted from unhealthy air generated in swamps. From this belief came the word "malaria," which means "bad air". The word is still used to describe a parasitic disease that remains one of the world's major public health problems. Efforts to find and isolate the causes of malaria make one of the greatest scientific detective stories of all time. Mosquitoes of the genus Anopheles were found to be implicated. But so far, their control is far from accomplished. Program features Dr. A. Murray Fallis, parasitologist with the Ontario Research Foundation and professor at the University of Toronto. Host is Lister Sinclair.