Paulus, On Sabinus, Book I. A father is not a competent witness for his son, nor a son for his father.

The Same, On Sabinus, Book I. If I have a grandson derived from one of my sons, and a granddaughter derived from another, under my control, Pomponius says that my consent will be sufficient to enable marriage to be contracted between them; which is correct.

Paulus, On Sabinus, Book I. If a son who is under paternal control should be passed over in his father’s will, and die during the lifetime of the latter, the will is not valid, and where there is a former one, it will not be broken. This is also the rule at the present time.

Paulus, On Sabinus, Book VII. Where anyone who, on account of age or ill health, cannot have children, appoints posthumous heirs, a former will is broken, because the nature of man and the capacity for procreation must rather be considered than a temporary defect or illness, by reason of which a man is deprived of the power of generation. 1Where, however, a man appoints a posthumous child as his heir who is to be born of the wife of another, the appointment will not be valid in law, for the reason that it is dishonorable. 2If I disinherit my son, and pass over my grandson born to said son, and appoint another person my heir, and my son survives, even though he should die before my estate is entered upon, my grandson cannot, nevertheless, break my will; so Julianus, Pomponius, and Marcellus hold. The case is different where my son is in the hands of the enemy and dies there, for my grandson in this instance can break my will, since, when his grandfather died, the right of the son was in suspense, and was not extinguished, as in the former instance. Where, however, the appointed heir rejects the estate, the grandson will be the lawful heir, as these words, “If he should die intestate”, have reference to the time when the will ceased to be valid, and not to that when the party died. 3But where I appoint a posthumous heir to be born of a woman whom it is wrong to marry, Pomponius does not think that the will is broken. 4If I have an adopted sister, I can appoint her posthumous child my heir, for the reason that if the adoption is annulled I can marry her.

Ad Dig. 28,5,10Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. III, § 553, Note 5.Paulus, On Sabinus, Book I. When anyone appoints heirs to different portions of different tracts of land, it will be the same as if they had not been appointed to certain portions of the same; for it is not easy to ascertain what their shares will be in the different tracts. Therefore, it is more expedient, as Sabinus says, for it to be considered that the testator had neither mentioned the land, nor the shares to which they were entitled.

Paulus, On Sabinus, Book I. Where the party who is appointed heir is substituted for a son, he will not be prevented from taking under the substitution, if he can do so after the death of the son. Again, on the other hand, he can be held liable to certain penalties under the will of the minor, although he may not be subject to any under that of the father.

Paulus, On Sabinus, Book I. If I am appointed an heir under the condition: “If I pay ten aurei”, and the party to whom I am ordered to pay the money refuses to accept it, the condition is held to have been complied with.

Paulus, On Sabinus, Book I. If anyone should appoint a son under paternal control his heir, and afterwards says: “If the said Titius, a son under paternal control, shall not be my heir, let Sempronius be my heir”; and the son enters upon the estate by the order of his father, the substitute will be excluded. 1Ad Dig. 29,2,7,1Windscheid: Lehrbuch des Pandektenrechts, 7. Aufl. 1891, Bd. III, § 595, Note 14.If the son, before he knew that he was the necessary heir of his father, should die leaving a son as his necessary heir, the grandson should be permitted to reject the estate of his grandfather for the reason that this privilege would also have been granted to his father. 2In every succession, anyone who is the heir to a party who is the heir of Titius, is also held to be himself the heir of Titius, nor can he reject the estate of the latter.

Paulus, On Sabinus, Book I. Where a slave is left to be selected by the legatee, we can make a choice but once. 1Labeo says that when a certain article or slave is bequeathed as follows: “Who will be mine when I die shall be given by my heir,” and the article or slave is held in common, the whole of it will be due. Cassius states that Trebatius gave it as his opinion that only the share owned by the testator is due; which is correct. 2Where a tract of land owned in common is devised, without mentioning the share belonging to the testator, but where he merely says “mine”, it is established that only his share will be due.