2. Every one has two ascendants at the first degree, his father and mother; four at the second degree, his paternal grandfather and grandmother, and his maternal grandfather and grandmother; eight at the third. Thus in going up we ascend by various lines which fork at every generation. By this progress sixteen ascendants are found at the fourth degree; thirty-two, at the fifth sixty-four, at the sixth; one hundred and twenty-eight at the seventh, and so on; by this progressive increase, a person has at the twenty-fifth generation, thirty-three millions five hundred and fifty-four thousand, four hundred and thirty-two ascendant's. But as many of the ascendants of a person have descended from the same ancestor, the lines which were forked, reunite to the first comnmon ancestor, from whom the other descends; and this multiplication thus frequently interrupted by the common ancestors, may be reduced to a few persons. Vide Line.