Cytology of Mycetozoa

Abstract

IN her paper entitled “The Life-History and Cytology of Didymium nigripes Fr.”, ¹ Dr. E. J. Cadman has made a valuable contribution to the literature on Mycetozoa. The principal points described by her are the following : the active swarm-cells possess what she terms a “centroblepharoplast” and cone apparatus connecting the nagellum with the nucleus ; the nucleus of the swarm-spores has four chromosomes ; a definite myxamœlig;boid stage occurs when all trace of cone-apparatus disappears ; the myxamœbæ unite in pairs as gametes to form a zygote or young plasmodium, and their nuclei also fuse ; the fusion nucleus contains eight chromosomes, a diploid number characteristic of all succeeding nuclei of the plasmodium ; meiosis occurs in the nuclei of the young sporangium before spore-formation, when a heterotypic division with four U-shaped chromosomes is swiftly followed by a homotypie division with four nearly spherical chromosomes.