Progress in physics and chemistry governs the development of modern medicine. From the time of Leeuwenhoek and his first successful microscope in the seventeenth century, man has been slowly penetrating deeper into the secrets of nature. It is a long cry from Leeuwenhoek's microscope to the binocular microscope with magnifications of 900, 1,500 and 2,000 diameters. Today we are on the eve of amazing discoveries which, in their importance and significance, rival those of William Harvey and Pasteur. The science of medicine is being revolutionized daily. Molecules which not long ago were theoretical entities are now clearly visualized by the electron microscope. The ordinary refractive microscope revealed nothing more concerning the morphology of spermatozoa than the contour of the head and number and approximate length of tails. All the finer details were hopelessly concealed. Fundamentally, we know little about spermatozoa, and that little may be summed up as (1) motility