Pomponius, On Quintus Mucius, Book XXII. A wife, or a husband, acquires the right to the produce of property which has been given by one to the other, that is to say, what either has been acquired by his or her labor, for example, by sowing; but if an apple should be plucked, or a tree cut down, it does not become the property of the party responsible for the act, just as it would not belong to any bona fide possessor, because the produce is not derived from his or her personal exertion.

Pomponius, On Quintus Mucius, Book XXII. It should be noted that obligations for the performance of services are sometimes subject to diminution, increase, and modification; for when a freedman is enfeebled, the patron loses his services which had already begun to be due. If, however, a freedwoman who had promised her services is raised to such a rank that it will be improper for her to render them to her patron, the obligation will be annulled by operation of law.

The Same, On Quintus Mucius, Book XXII. When a slave in whom we have the usufruct stipulates expressly for the benefit of the owner, for something to be derived from the property of the usufructuary, or from his own services, it is acquired for the benefit of the owner of the property. Means should, however, be taken to ascertain by what action the usufructuary can recover it from the owner of the property. Again, if a slave serves us in good faith, and stipulates expressly for the benefit of his master for something which he can acquire for us, he will acquire it for him. We must examine by what action we can recover it from him, and what our Gaius has stated on this point is not unreasonable, namely: that, in both cases, the property can be recovered from the owner by a personal action.