The Pap smear, a diagnostic technique
Late in the 1920s Dr. George Papanicolaou began to develop a laboratory method to diagnose cancer of the uterus based upon observation of individual cells. In 1943 he and Herbert Traut published a paper describing the new technique. As a universally used means of early detection, the Pap smear has brought about a sharp decline in the cervical cancer death rate. AP/Wide World Photo