Wolffian Ducts

**Definition:** A pair of excretory ducts of the middle kidneys (MESONEPHROI) of an embryo, also called mesonephric ducts. In higher vertebrates, Wolffian ducts persist in the male forming VAS DEFERENS, but atrophy into vestigial structures in the female.

**Tree numbers:** - A16.935

**Synonyms:** - Mesonephric Ducts - Wolffian Duct