plebeian assembly were valid under certain conditions, and that the Publilian and Hortensian laws removed these restrictions. In discussing the Valerio-Horatian law (p. 32) an attempt was made to show that a measure adopted by the concilium plebis acquired the force of law, if it was subsequently ratified by the patrician senators. Between 449 and 339, then, in the case of both the comitia centuriata and the concilium pleblis, a bill, in order to become a law, required, first, favorable, action by the popular assembly, then the sanction of the patrician senators. In other words, the method of procedure was the same in both cases. Now one clause of the Publilian law, as we have already seen, provided that in the case of the centuriate comitia the auctoritas patrum should precede the action of the comitia. If we assume that the same change was made in the case of the plebeian assembly, and the assumption is not improbable, the relation which the three laws bear to one another is clear. It may be stated as follows: from 449 to 339 a bill became a law if it was favorably acted on by the centuriate comitia or by the plebeian tribal assembly, and subsequently approved by the patrician senators; from 339 to 287 the auctoritas patrum preceded in both cases; after 287 the preliminary approval of the patrician element in the senate was necessary in the case of the centuriate assembly, but unnecessary for the action of the plebeian tribal assembly. One difficulty in the situation has not yet been spoken of. The fact has already been mentioned (p. 33) that in 447 a patricio-plebeian tribal assembly comes into existence. After that date, then, there are two tribal assemblies, one made up of plebeians, the other of both patricians and plebeians. Ancient writers do not carefully distinguish between these two bodies, so that it is often difficult to say to which one reference is made. However,
