One of the prytaneis [sc. in classical Athens], chosen by lot, was known as the chairman. It was not possible for the same man to serve as chairman twice. He keeps the keys of the temple in which the public monies [are kept], and also the public seal. Whenever the prytaneis convene the council or the people, the chairman selects by lot nine proedroi, one from each tribe except the [tribe] in prytany. And again from these nine he selects by lot one chairman and hands over the business [to him];[1] he himself introduces the lawsuit[s] and, in accordance with law, ensures that everything happens and nothing is omitted in the instruction of the jurors.