The Structure and Manner of Division of the Nuclei in the Vegetative Mycelium of the Fungi Imperfecti

I. Phyllosticta sp

Abstract

The nuclei in the germ tubes and mycelium of the imperfect fungus Phyllosticta sp. do not divide in a manner directly comparable to ordinary mitosis. A mitotic apparatus such as a spindle or metaphase plate was not observed. At the beginning of division the granular chromatin contracts usually forming a tightly packed complex of filaments. Counts of these filaments could not be made. As division proceeds this complex elongates, constricts at the midregion and at the end of division the extremities pull apart forming the chromatin portions of the sister nuclei. During division the original central body becomes separated from the dividing chromatin and progressively smaller. At the end of division the central body is either a tiny remnant of its former self or has completely disappeared. New central bodies are formed in the maturing sister nuclei.