It has been said that "marriage is a mutual agreement of man and woman to live together in the relation and under the duties of husband and wife, sharing each other's fate or fortune for weal or woe until parted by death." 1 A recent definition of the term as used in common speech, is "The act of marrying or uniting a man and woman as husband and wife; the legal union of a man and woman for life; the state or condition of being married, wedlock."2 Herbert Spencer, in his Principle of Sociology says that "the marital relations have gradually evolved;" and that the first stage was promiscuity, joined with "indefinite polygamy" to that succeed ployandry; ' 'in some cases the husbands being strangers, in others akin, and usually brothers," higher in rank stands polygamy, "with which Hebrew history makes us acquainted in our childhood; and in due time was evolved monogamy, the natural form of sexual relation for the human race."