Ultrastructural investigation of the ovary structure ofOphyiulus pilosus (Myriapoda,Diplopoda)

Summary Histological and ultrastructural investigations of diplopod ovary structure have revealed that oogonia and early meiotic oocytes develop only in the laterodorsal parts of the ovarian wall, where they form groups called germ nests. Euplasmic growth forces diplotene oocytes out of the ovarian wall and into the lumen of the ovary, which leads to the formation of ovarian sacs. Ovarian sacs constitute separate structural-functional units built of a centrally situated oocyte and the epithelial cover. Being turned with their basal parts to the surface of the oocyte and showing no signs of any synthetic nor secretory activity, the epithelial cells of the ovarian sac wall cannot be referred to as typical follicular cells. That is why oogenesis of diplopods must be regarded as solitary.