<Tr> <Th_colspan="2"> Identifiers </Th> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The development of the gonads is part of the prenatal development of the reproductive system and ultimately forms the testes in males and the ovaries in females . The gonads initially develop from the mesothelial layer of the peritoneum . </P> <P> The ovary is differentiated into a central part, the medulla, covered by a surface layer, the germinal epithelium . The immature ova originate from cells from the dorsal endoderm of the yolk sac . Once they have reached the gonadal ridge they are called oogonia . Development proceeds and the oogonia become fully surrounded by a layer of connective tissue cells (pre-granulosa cells) In this way, the rudiments of the ovarian follicles are formed . </P>

Where do the testes develop in the embryo