<i>Echinostoma hortense</i> ASADAの雌性生殖器と卵黄細胞・卵黄顆粒に関する研究

Abstract

For the purpose to study morphology and fine structures of the reproductive cells such as vitelline cells and vitelline globules as well as the structural arrangement of the female reproductive organ and the mechanism of the formation of operculum in Echinostoma hortense Asada, electron microscope observations were conducted, and the results of this study are briefly presented in the following. 1. The morphology of Echinostoma hortense has a basic structural arrangement as observed in general trematodes, and it is a characteristic feature of this trematode that numerous vitelline glands are distribted in the posterior half of this worm and many vitelline globules in the insemination chamber.2. This insemintion chamber of the worm is the thickened, enalarged oviduct, and many sperms and ovums are detected in it.3. There can be recognised the formation of egg-shell in the proximal part of uterus in the observation of live worms, and in the formation of operculum there are seen one or two vitelline cells whose sceleroma is delayed at one polar end of the longitudinal axis and at this site the egg-shell is formed.4. In the electron microscope observations on fine structures of vitelline glands it has been possible to trace various steps from the beginning of vitelline cells to the ones that are mature and free. In those cells that are still immature there can be already detected groups of vitelline globules of high electron density.5. Electron microscope observations of the fine structures of mature vitelline cells revealed two different kinds of vitelline globules; namely, one group was composed of vitelline globules that existed from the immature stage of the cell and the other was of those globules produced from fibroid bodies and were relatively less eleçtron dense globules.6. There are two kinds of cells in the gland cells of Mehlis' gland of this trematode, and their morphological differences are that B-type cell located near the ootype has two kind of secretory globules while A-type cell located farther away possesses only a single but different secretory globules.