Zavim, Chapter Two, Mishnah One
1) All persons become unclean through zivah, even converts, even slaves whether freed or not, a deaf-mute, a person of unsound senses, and a minor, a eunuch whether [he had been castrated] by man, or was a eunuch from [the time of seeing] the sun.
2) With regard to a tumtum and an androgynous [person], they place upon him the stringencies for a man and the stringencies for a woman: they defile through blood like a woman, and through eggy [substance] like a man.
a) Their uncleanness still remains in doubt.
Section one: The laws of becoming unclean through seeing zivah (zov) apply to any Jew of any status, including converts, freed and non-freed slaves and people who legally are considered as lacking awareness. They apply to all males, even those who have been castrated, either by another human being or were born as eunuchs.
Section two: The laws of being a zav apply only to a man and the laws of being a zavah apply only to a woman. They also work differently. Our mishnah asks what to do with two categories of people who exist somewhere in between, neither male nor female? A tumtum does not have signs of being either male or female whereas an androgynous person has both (according to the rabbinic definition).
The rule with regard to the stringencies that apply to either sex apply to them. So if they have blood flow, it defiles as it does for a woman. And if they have zov discharge (eggy substance) then they defile as it does for a man. However, the status of their defilement is doubtful. For if they see blood, they might be a male for whom blood does not defile. And if they see a discharge of zov, they might be female for whom such discharge does not defile. Therefore, in either case they only doubtfully defile.