Electron micrographs of the anterior part of the mid-gut and hepatic caeca of Blatta orientalis Linn, show epithelial cells in both secretory and absorptive cycles. The epithelial cells possess microvilli and their lateral margins are provided with irregularly shaped projections that interdigitate with neighbouring cells. Vacuole-like structures were observed in association with the mitochondria of absorptive and degenerating cells. These vacuoles, it is suggested, represent degeneration products. Bundles of saccules and associated groups of vacuoles and vesicles represent the Golgi rods and granules of light microscopy. Epithelial cells engaged in absorption differ from those in which the elaboration of secretion is taking place, in the arrangement of the Golgi saccules and vacuoles, in the size of the Golgi vacuoles, in the distribution of the mitochondria, and in the possession of a less extensive endoplasmic reticulum.
L. Threadgold, R. Gresson
Proceedings of The Royal Society B: Biological Sciences