Ulpianus, On Sabinus, Book XXXVII. Where a male or female ward has a guardian, and becomes insane, he or she will still remain under guardianship while in this condition. This is the opinion of Quintus Mucius, and was approved by Julianus; and we adopt the rule that curatorship shall cease where the age requires guardianship. Therefore, if wards have guardians, they are not, by reason of their insanity, placed under curatorship; and if they have none, and insanity should attack them, they can, nevertheless, have guardians, because the Law of the Twelve Tables is understood not to apply to wards of either sex. 1For the reason, however, that we do not permit agnates to be the curators of minors, I have thought that even though a minor under the age of twenty-five may be insane, a curator should be appointed for him; not because he is insane, but for the reason that he is a minor, just as if the impediment of age existed. We make this distinction in the case of a person whose age subjects him to curatorship or guardianship, and it is not necessary to appoint a guardian for him on account of his demented condition. This the Emperor Antoninus Augustus stated in a Rescript, since provision should be made for age rather than insanity, during a certain time. 2Where a ward of either sex desires to institute proceedings against his or her lawful guardian, or if the latter desires to do so along with him or her, and a demand is made for a curator, shall he be appointed on the application of the ward, or on that of his or her adversary? It should be remembered that a curator can be appointed whether a ward sues or is sued, but this cannot be done unless he for whom the curator must be appointed requests it. Hence Cassius states in the Sixth Book that no one can be appointed a curator under such circumstances, unless he is present, and the party requesting his appointment is also in court. Therefore, a curator cannot be appointed for an infant. Cassius says that if a minor does not wish to ask for a curator, in order to prevent suit from being brought against him, he should be compelled to make application for one by the Prætor. 3Pomponius states in the Sixteenth Book, that a curator of this kind can be appointed at any place and at any time. 4If a minor petitions for such a curator, and does not state for what purpose he wishes him, shall he be appointed for all the controversies in which the minor may be involved? Celsus says that Servius has decided that the curator should be considered to be appointed for the transaction of all business.

Ulpianus, On Sabinus, Book XXX. Where minors are arrogated or deported, they cease to have guardians. 1The guardianship also terminates where a ward is reduced to slavery. 2Guardians cease to hold office for several other reasons, for example, where either the ward or the guardian is captured by the enemy. 3When a guardian is appointed for a certain time, at the expiration of that time he ceases to hold his office. 4Moreover, a guardian ceases to hold his office where he is removed on account of being suspected. 5Where a guardian is appointed under a certain condition, it also happens that when the condition is fulfilled, he ceases to be a guardian.

The Same, On Sabinus, Book XXXVII. If anyone appoints a guardian under a condition or from a certain date, another guardian should be appointed in the meantime, even though the ward may already have a legal guardian; for it must be remembered that legal guardianship is not operative so long as the appointment of a testamentary guardian is expected. 1Where the office of guardian devolves upon one appointed by will, and the testamentary guardian is afterwards excused from serving; we can say in this instance that another should be appointed in the place of the one who was excused, and that the office does not revert to the legal guardian. 2We also say that, if the guardian should be removed, the same rule will apply; for he retires in order that another may be appointed. 3If, however, the testamentary guardian should die, the office will revert to the original guardian, because in this instance the Decree of the Senate does not apply. 4It is evident that if two or more testamentary guardians are appointed, and one of them dies or forfeits his civil rights, another can be appointed in his stead; but if neither of them survives, or retains his civil rights, the legal guardianship will be established.

The Same, On Sabinus, Book XXXVII. There is no doubt that legal guardianship is lost by a change of the civil status of the ward, even if he should not have lost his citizenship.