Ultrastructure of Mitosis In the Aquatic Fungus Catenaria Anguillulae

SUMMARYThe ultrastructure of mitosis in the zoosporangia of the water mold Catenaria anguillulae has been studied. The nuclear divisions prior to the formation of zoospores are mitotic. Centrioles are associated with but not connected to the spindle which is intranuclear. The nuclear membrane persists throughout the division process.It is suggested that anaphase separation of the daughter chromosomes is accomplished by the elongation of spindle tubules of the interzonal region. Telophase is marked by the rounding up of the daughter nuclei with the exclusion from the nucleus of a central, spindle-shaped structure which is then apparently broken down.