"Non-fraternal polyandry" occurs when the wives' husbands are unrelated, as among the Nayar tribe of India, where girls undergo a ritual marriage before puberty, and the first husband is acknowledged as the father of all her children. However, the woman may never cohabit with that man, taking multiple lovers instead; these men must acknowledge the paternity of their children (and hence demonstrate that no caste prohibitions have been breached) by paying the midwife. The women remain in their maternal home, living with their brothers, and property is passed matrilineally. A similar form of matrilineal, de facto polyandry can be found in the institution of walking marriage among the Mosuo tribe of China.