A man counts as his sons all the sons of his brothers or of his virtual wives; but the sisters of these sons are his sisters. A woman calls the sons and daughters of her brothers her nephews and nieces, but the children of her sister are counted as her own children; because their father is virtually her husband. Among the Omahas a man calls his sister’s children nephews and nieces. A person of either sex counts as grandchildren all those who are called the children of his sons, daughters, nephews, and nieces, or reputed as such. A man counts as uncles all those whom his mothers call “brothers”; and as aunts all the sisters of his father and the wives of his uncles. A man has for brothers-in-law the husbands of his father’s sister; for they are the real or virtual husbands of his sisters; a woman has them for virtual husbands.[935] Various prohibitions of marriage result from these conventional kinships. A man may not marry the women that he calls daughters of a sister, or grand-daughters, etc. A woman may not marry the men who are her sons, the sons of her sister, of her aunt or of her niece, or who are her brothers, etc.[936] But an Omaha may marry any woman who is not a blood relation, provided that she does not figure among the prohibited affinities.[937] We have not such detailed information regarding the other Redskin tribes; but we know enough of them to be certain that their systems of kinship are very analogous to those of the Iroquois Senecas and the Omahas. Filiation is everywhere maternal, except in certain tribes in the course of evolution; nearly everywhere also it is a crime to marry a woman having the same _totem_.[938] Among the Mandans, Pawnies, and Arickaries, a man calls his brother’s wife his wife also. Among the Crows a woman calls her husband’s brother’s wife her “comrade”; but among the Winebagos she calls her “sister.” In some tribes a man’s wife’s sister’s husband is called his “brother.”[939] Some very severe and inconvenient rules of decency have resulted from these fictitious kinships, with their prohibitions of marriage. Thus, among the Omahas, the young girls may only speak to their father, brother, and grandfather. A woman avoids passing before her daughter’s husband as much as possible; and, unless under extraordinary circumstances, a woman does not speak directly to the father of her husband. A man never addresses a word to the mother or grandmother of his wife.[940] In the last century, among the Iroquois, a young man was dishonoured if he stopped to converse in public with a young girl who was certainly within the prohibited degree of kinship.[941] For a young Iroquois girl to call the husband of her aunt by his personal name was considered a grave act, indicating a culpable _liaison_.[942]