In order to the better understanding of this matter, it is necessary at the outset to make a distinction between four kinds or varieties of inheritance. The most generally recognised is _direct inheritance_,--that in which the children partake of the qualities of the father and mother. But a child may not resemble either parent, while it bears a striking likeness to an uncle or aunt. This constitutes _indirect_ inheritance. Again, a child may be more like one of its grandparents than either its father or mother. Or, what is still more astonishing, it may display some of the characteristics possessed only by a remote ancestor. This form of inheritance is known by the scientific term _atavism_, derived from the Latin word _atavus_, meaning an ancestor. It is curious to note in this connection that sometimes a son resembles more closely his maternal than his paternal grandsire in some male attribute,--as a peculiarity of beard, or certain diseases confined to the male sex. Though the mother cannot possess or exhibit such male qualities, she has transmitted them through her blood, from her father to her son. The fourth variety of inheritance is that in which the child resembles neither parent, but the first husband of its mother. A woman contracting a second marriage, transmits to the offspring of that marriage the peculiarities she has received through the first union. Breeders of stock know this tendency, and prevent their brood-mares, cows, or sheep from running with males of an inferior stock. Thus the diseases of a man may be transmitted to children which are not his own. Even though dead, he continues to exert an influence over the future offspring of his wife, by means of the ineffaceable impress he had made in the conjugal relation upon her whole system, as we have previously mentioned. The mother finds in the children of her second marriage '... the touch of a vanished hand, And the sound of a voice that is still.' A child may therefore suffer through the operation of this mysterious and inexorable law, for sins committed not by its own father, but by the first husband of its mother. What a serious matter, then, is that relation between the sexes called marriage! How far-reaching are its responsibilities!