The increasing number of special judiciary commissions and the institution of standing courts limited more and more the judicial activity of the centuriate assembly; but the tribunes of the plebs kept alive the feeling of popular sovereignty in this sphere by the occasional prosecution of some notorious offender.[1536] The continuance of the centuriate judicial function is proved by the Cassian plebiscite of 137, which provided for the use of the ballot in all iudicia populi excepting in perduellio,[1537] and by the lex Caelia, 108, which removed the exception.[1538] The limitation upon popular jurisdiction by the special court is said to have begun as early as 414, when, according to Livy,[1539] a senatus consultum authorized the appointment of a quaestio extraordinaria to discover and punish the murderers of M. Postumius, a tribune of the soldiers with consular power. The plebs, consulted as to the presidency of the court, left it to the consuls. The instance may be an anticipation of later usage. The case of wholesale poisoning by Roman matrons, 331, was investigated, and a hundred and seventy matrons were condemned, by an extraordinary court, which evidently owed its existence to a senatus consultum without the coöperation of the people.[1540] The same is true of the quaestio appointed by the senate under dictatorial presidency in 314 to inquire into charges of conspiracy of the leading men in certain allied states. The dictator extended the inquiry to Rome, and after his resignation the consuls continued the work. Livy’s account of this affair assumes that the senate had full power to appoint such commissions.[1541] It did in fact possess the right without the coöperation of the people to institute quaestiones extraordinariae for the trial of allies or other aliens in crimes which menaced the security of Rome. In the period between the Hortensian legislation and the Gracchi in two recorded instances it dared on its own responsibility to appoint such courts for the trial of citizens.[1542] These were usurpations; for as the laws of appeal forbade the putting to death of a citizen unless condemned by the people, a special court with capital jurisdiction over citizens could not be constitutionally established excepting with the consent of the assembly. This right of the people was considered a legislative equivalent of their judicial power, which the vast expansion of their state made it impossible for them directly to exercise.[1543] The court which tried and condemned the insurgent garrison of Rhegium in 270 was instituted accordingly by a plebiscite authorized by a senatus consultum.[1544] Most probably the court in this case was the senate itself, just as in 210, when the plebiscite of L. Atilius gave it full power to judge and punish the Campanians for revolt.[1545] The appointment of special courts for the detection and punishment of aliens for illegal usurpation of the citizenship, which belonged originally to