The Wolffian duct, also known as the mesonephric duct, is a structure that plays a crucial role in the development of the male reproductive system. It forms during embryonic development and is responsible for the formation of several male reproductive organs, including the epididymis, vas deferens, and seminal vesicles. In females, the Wolffian duct typically regresses and does not contribute to the reproductive system. Instead, the Müllerian duct develops into female reproductive structures such as the uterus and fallopian tubes. The presence or absence of hormones during development determines the fate of the Wolffian duct.