| Abstract: | SYNOPSIS. Light- and electronmicroscopic studies of noncontracted and contracted regions of Nematocystis magna Schmidt (Gregarinida) trophozoites revealed that their peristalsis-like movements are accompanied by conformational changes in the folded limiting membrane and underlying layer of transverse fibrils. Noncontracted and contracted regions of individual trophozoites had “folded'’and “superfolded'’configurations respectively. Measurements of periodicity and through-focus studies, together with the sequential use of the same Araldite sections for light and electron microscopy, aided in identification of longitudinal fibrils of varying sizes (light microscopy) with specific conformations of the epicytary folds (electron microscopy) in contracted and noncontracted states. |
