Foetal ovary, light micrograph. A mid-gestation foetal ovary showing three main cell types. First are many oocytes entering meiosis with duplicated chromosomes. These germ cells will be arrested at the diplotene phase of meiotic prophase and remain thus until, or if, ovulated during postnatal life. Second are several dozen densely-stained cells that are degenerating by apoptosis and referred to as pyknotic germ cells. Third are the large numbers of nuclei of somatic cells, those which are elongated forming loosely-defined germ cell 'nests', and many others associated with the oocytes. The latter cells are pregranulosa cells that will eventually develop into granulosa/follicular cells of future ovarian follicles. Acrylic resin section, haematoxylin-eosin stain. Magnification: x180 when width printed at 10cm.