On pg. 212 of D’Ooge’s book.
Publius now had stayed at Rome for the whole year and had seen many sights of the city, and he had made many friends for himself. Everyone liked him; everyone could expect well from him. Everyday, Publius attended the schools of the philosophers and of the grammarians with such great zeal to show himself to be a bright example to others. He was often with his father in the senate house; which he did to listen and to see the greatest men of the republic. When he was sixteen years old, he laid aside the golden bulla and the fringed toga as was the Roman custom, and he took up the toga of manhood. Moreover, the toga of manhood was entirely white, but the fringed toga had a purple stripe on the margin. To lay aside the fringed toga and to take up the toga of manhood was a very pleasing thing to a Roman boy, because he was considered a man and a Roman citizen afterwards.
These things coming to pass, Lentulus wrote this letter to his wife:
“Marcus greets his Julia. If you are well, it is well; I am well. I received your letter. I now send this letter from Rome by means of a most faithful slave so that you may know of our Publius as quickly as possible. For today, I gave him the toga of manhood. I arose before dawn, and first, I removed the golden bulla from his neck. This being consecrated by the Lares and sacrifices being made, I dressed him with the toga of manhood. Meanwhile, many friends had arrived with a crowd of the best citizens and of noble followers who led Publius out from the house to the forum. There, he was enrolled as a citizen, and his name, Publius Cornelius Lentulus, was inserted among the Roman citizens. Everyone was very amiable to him and they foretell great things from him. For he is wiser than his equals and he possesses great talent. Take care that you are well.”