Julianus, Digest, Book LIX. Neither statutes nor decrees of the Senate can be written in such a way as to include all cases at any time which may arise; but it is sufficient if they include such as frequently occur.

Julianus, Digest, Book LIX. Titius, having disinherited his son, appointed a foreign heir under a condition. The question arose, if after the death of the father and while the condition was pending, the son should marry a wife and have a child, and then should die, and the condition imposed upon the appointed heir should not subsequently be complied with, whether the estate would belong by law to the posthumous grandson, or to the grandfather. The answer was, that a child conceived after the death of its grandfather cannot, as the proper heir, obtain his estate, or, as his cognate, acquire prætorian possession of the same; for the reason that the Law of the Twelve Tables calls to the succession him who was in existence at the time of the death of the person the disposition of whose estate is in question.

Julianus, Digest, Book LIX. The Prætor, by his Edict also, on the ground of their being next of kin, promises the possession of an estate to those who were cognates of the deceased at the time of his death. For, although it is customary to call those cognates grandsons who were conceived after the death of their grandfather, this designation is not proper, but susceptible of abuse, as it is based on analogy. 1If anyone should leave his wife pregnant, and a mother and a sister, and the mother should die during the lifetime of his wife, and his wife should afterwards have a dead child, the estate will pass to the sister alone, as the heir at law; because it is certain that the mother died at a time when she could not lawfully have acquired the estate.