Insect Sperm: Their Structure and Morphogenesis

The thorough descriptive studies by the early cytologists Meves (1901, 1907), Retzius (1904, 1909), Bowen (1920, 1922 a-c, 1924), Pollister (1930), and Johnson (1931) provided later workers with a remarkably accurate picture of the microscopic anatomy of insect spermatozoa and of spermiogenesis in several insect species . Their light microscope observations were necessarily lacking in detail, however, and since the advent of the electron microscope, an increasing number of cell biologists have undertaken to extend our understanding of the structure of insect germ cells. Some have confined their attention to spermiogenesis or the morphology of mature spermatozoa of a particular species, while others have been concerned with the comparative morphology of single sperm organelles. Although there are by now many relevant papers of limited scope widely dispersed in the biological literature, there seems to be no single reference to which one can turn for an overview of the structure and development of the insect spermatozoon. In this review an effort is made to gain some perspective from a synthesis of these fragmentary accounts supplemented by the author's own observations based on electron microscopic examination of nearly two hundred insect species.'