23 A legacy of selection, that is, when a testator directs the legatee to select one from among his slaves, or any other class of things, was held to be given subject to an implied condition that the legatee should make the choice in person; so that if he died before doing so the legacy did not pass to his heir. By our constitution, however, we have made an improvement in this matter, and allowed the legatee's heir to exercise the right of selection, although the legatee has not done so personally in his lifetime; which enactment, through our careful attention to the subject, contains the further provision, that if there are either several colegatees to whom a right of selection has been bequeathed, and who cannot agree in their choice, or several coheirs of a single legatee, who differ through some wishing to choose this thing and others that, the question shall be decided by fortune--the legacy not being extinguished, which many of the jurists in an ungenerous spirit wished to make the rule--; that is to say, that lots shall be drawn, and he on whom the lot falls shall have a priority of choice over the rest. 24 Three persons only can be legatees who have testamentary capacity, that is, who are legally capable of taking under a will. 25 Formerly it was not allowed to leave either legacies or fiduciary bequests to uncertain persons, and even soldiers, as the Emperor Hadrian decided by rescript, were unable to benefit uncertain persons in this way. An uncertain person was held to be one of whom the testator had no certain conception, as the legatee in the following form: 'Whoever bestows his daughter in marriage on my son, do thou, my heir, give him such or such land.' So too a legacy left to the first consuls designate after the writing of the will was held to be given to an uncertain person, and many others that might be instanced: and so it was held that freedom could not be bequeathed to an uncertain person, because it was settled that slaves ought to be enfranchised by name, and an uncertain person could not be appointed guardian. But a legacy given with a certain demonstration, that is, to an uncertain member of a certain class, was valid, for instance, the following: 'Whoever of all my kindred now alive shall first marry my daughter, do thou, my heir, give him such and such thing.' It was, however, provided by imperial constitutions that legacies or fiduciary bequests left to uncertain persons and paid by mistake could not be recovered back. 26 An afterborn stranger again could not take a legacy; an afterborn stranger being one who on his birth will not be a family heir to the testator; thus a grandson by an emancipated son was held to be an afterborn stranger to his grandfather.