Abstract
This paper shows the process of egg shell formation on the example of the trematode Dendrithobilharcia purveru lenta (Braun, 1901). It was established that the process of egg shell formation is associated with morphofunctional features of vitelline glands and Mehlis’ glands. Vitellines’ granules in the ootype or proximal uterus, release proteins for tanning under the influence of agents. Mehlis’ glands of trematode Dendrithobilharcia purverulenta is a multifunctional organ that provides: activation of the process of release of the shell material from vitelline glands; the formation of a resistant egg shell as a result of layering the shell material on it; facilitating the process of moving eggs through the uterus loops due to "mucosal" substances secreted by the second type of cells. Thus, the vitelline follicles Mehlis’ glands of trematode Dendrithobilharcia purverulenta represent a single functional unit that ensures the formation of a resistant egg shell.