FINE STRUCTURE OF THE SPERMATOZOID OF ZAMIA WITH SPECIAL REFERENCE TO THE FLAGELLAR APPARATUS

The locomotor apparatus of the spermatozoid of Zamia integrifolia consists of numerous flagella having the typical 9 + 2 substructure connected through basal bodies to a spiral band of complex structure. Basal bodies have a fine structure somewhat resembling that found in algae, mosses, and ferns, but they are much longer. They are composed of a circle of 9 double fibers just beneath the plasma membrane, changing to 9 doublets interconnected by fibrils in a star-pattern, giving over to a centriolar type of 9 triplet fibers embedded in an electron-dense layer of the spiral band, and ending in a “cartwheel” configuration. A system of microtubules arranged in a spiral, secondary to the flagellated spiral, is thought to underlie the plasma membrane in flagellated regions. It is suggested that this system accounts for “euglenoid” movements of the sperm. Other details of cellular fine structure are described.