On the failure of the direct line, the right of succession must diverge to the collateral branches.  The degrees of kindred are numbered by the civilians, ascending from the last possessor to a common parent, and descending from the common parent to the next heir:  my father stands in the first degree, my brother in the second, his children in the third, and the remainder of the series may be conceived by fancy, or pictured in a genealogical table.  In this computation a distinction was made, essential to the laws and even the constitution of Rome; the agnats, or persons connected by a line of males, were called, as they stood in the nearest degree, to an equal partition; but a female was incapable of transmitting any legal claims; and the cognats of every rank, without excepting the dear relation of a mother and a son, were disinherited by the Twelve Tables, as strangers and aliens.  Among the Romans a gens or lineage was united by a common name and domestic rites; the various cognomens or surnames of Scipio or Marcellus distinguished from each other the subordinate branches or families of the Cornelian or Claudian race:  the default of the agnats, of the same surname, was supplied by the larger denomination of gentiles; and the vigilance of the laws maintained in the same name the perpetual descent of religion and property.

A similar principle dictated the Voconian law, which abolished the right of female inheritance.  As long as virgins were given or sold in marriage, the adoption of the wife extinguished the hopes of the daughter.  But the equal succession of independent matrons supported their pride and luxury, and might transport into a foreign house the riches of their fathers.  While the maxims of Cato were revered, they tended to perpetuate in each family a just and virtuous mediocrity:  till female blandishments insensibly triumphed, and every salutary restraint was lost in the dissolute greatness of the republic.  The rigor of the decemvirs was tempered by the equity of the praetors.  Their edicts restored and emancipated posthumous children to the rights of nature; and upon the failure of the agnats they preferred the blood of the cognats to the name of the gentiles, whose title and character were insensibly covered with oblivion.  The reciprocal inheritance of mothers and sons was established in the Tertullian and Orphitian decrees by the humanity of the senate.  A new and more impartial order was introduced by the Novels of Justinian, who affected to revive the jurisprudence of the Twelve Tables.  The lines of masculine and female kindred were confounded:  the descending, ascending, and collateral series was accurately defined; and each degree, according to the proximity of blood and affection, succeeded the vacant possessions of a Roman citizen.