[The fine structure of the midgut of mite Myobia murismusculi].

The pattern of digestion in females of Myobia murismusculi was studied with light and electron microscopy. The midgut consists of a stomach and two pairs of blind caeca. The stomach is connected dorsoposteriorly with the excretory organ, that leads externally to an anal opening via the cuticle-lined rectum. No differences were found between the stomach and its caeca. The midgut epithelial cells are of a single type. Their fine structure and gut contents greatly vary depending on different physiological conditions of the mite. Four stages of digestion can be shown with electron microscope. Pino- and phagocytose takes place in the same cells. At an active stage of digestion numerous pinocytic canals were observed in the midgut cells. At each stage of the digestive cycle groups of flat cells are present in the midgut epithelium. They do not take part in the intracellular digestion of food material. Cytoplasmic processes from the underlying cells of coxal glands project into the midgut cells through the orifices in the gut basal lamina.