The Hormones and Development of One's Sex The objectives of this article as I saw them were, (1) to show how fetal gonads acquire the ability to function as endocrine organs, and (2), to show the mechanisms by which the endocrine secretions modulate male development. The researchers went through an extremely extensive explanation of the formation of the sexual phenotypes by detailing the development of germ cells. They explained how women's and men's gonads appear identical until Leydig cells, which synthesize testosterone, appear in the connective tissue. This is when differentiation