Abstract
THE development of technics that permit investigation of biologic specimens in the electron microscope took place shortly after the instrument became widely available commercially in the late 1940's.1 2 3 4 5 6 7 8 The rapid application of this instrument with its resolving power of 10 to 20 Ň to the problems raised by cytologists has resulted in an extensive literature. The study of human disease has been restricted by the lack of data concerning normal variations as well as the sampling problem inherent in electron microscopy. Material for electron microscopy obtained at autopsy is generally not usable owing to autolytic changes. This has limited most . . .