explained,[75.2] but a large body of evidence points to the conclusion that this custom of mutual avoidance is simply a precaution to prevent improper relations between the two. Hence a brief consideration of it is appropriate in this place; for to all appearance the custom, though it may be wholesome and beneficial in practice, has originated purely in superstition. But before giving my reasons for thinking so it may be well, for the sake of those who are unfamiliar with savage etiquette, to illustrate the practice itself by a few examples.[75.3] [Sidenote: The custom of avoiding a mother-in-law and other relations by marriage among the Boloki of the Congo.] Speaking of the Boloki, a Bantu tribe of the Upper Congo, an experienced missionary, the Rev. John H. Weeks, writes as follows: “Perhaps this will be the best place in which to make a few remarks on the mother-in-law. She and her son-in-law may never look on each other’s face. I have often heard a man say, ‘So-and-so, your mother-in-law is coming,’ and the person addressed would run into my house and hide himself until his wife’s mother had gone by. They can sit at a little distance from each other, with their backs to one another, and talk over affairs when necessary. _Bokilo_ means mother-in-law, daughter-in-law, brother-in-law, father-in-law, sister of mother-in-law, brother of father-in-law, wife of wife’s brother, and in fact any relation-in-law. _Bokilo_, the noun, is derived from _kila_ = to forbid, prohibit, taboo, and indicates that all bearing the relationship of {76} _bokilo_ can have no intimate relationship with one another, for it is regarded as incestuous; and it is according to native ideas just as wrong for a daughter-in-law to speak or look at her husband’s father, as for the son-in-law to speak or look at his wife’s mother. Some have told me that this was to guard against all possibility of cohabitation, ‘For a person you never look at you never desire.’ Others have said, ‘Well, don’t you see, my wife came from her womb.’ I am strongly inclined to the opinion that the former is the real reason.”[76.1]