The _provocatio_ had always been the challenge to the decision of a magistrate; but in these standing courts the actions of the president and of the _judices_ who sat with him were practically indistinguishable, and the sentence pronounced was in no sense a magisterial decision. The courts had also been instituted to avoid the clumsiness of popular jurisdiction; but this clumsiness would be restored, if their decision was to be shaken by a further appeal to the Comitia. Gracchus, in fact, when he proposed this law, was not thinking of the ordinary course of jurisdiction at all. He had before his mind the summary measures by which the senate took on itself to visit such epidemics of crime as were held to be beyond the strength of the regular courts, and more especially the manner in which this body had lately dealt with alleged cases of sedition or treason. The investigation directed against the supporters of his brother was the crucial instance which he brought before the people, and it is possible that, at a still later date, the inquiry which followed the fall of Fregellae had been instituted on the sole authority of the senate and had found a certain number of victims in the citizen body. Practically, therefore, Gracchus in this law wholly denied, either as the result of experience or by anticipation, the legality of the summary jurisdiction which followed a declaration of martial law. In the creation of these extraordinary commissions the senate never took upon itself the office of judge, nor was the commission itself composed of senators appointed by the house. The jurisdiction was exercised by a magistrate at the bidding of the senate, and the court thus constituted selected its assessors, who formed a mere council for advice, at its own discretion. It was plain that, if the law was to be effective, its chief sanction must be directed, not against the corporation which appointed, but against the judge. The responsibility of the individual is the easiest to secure, and no precautions against martial law can be effective if a division of authority, or even obedience to authority, is once admitted. Gracchus, therefore, pronounced that criminal proceedings should be possible against the magistrate who had exercised the jurisdiction now pronounced illegal.[594] The common law of Rome went even further, and pronounced every individual responsible for illegal acts done at the bidding of a magistrate. The crime which the magistrate had committed by the exercise of this forbidden jurisdiction was probably declared to be treason: and, as there was no standing court at Rome which took cognisance of this offence, the jurisdiction of the Comitia was ordained. The penalty for the crime was doubtless a capital one, and by ancient prescription such a punishment necessitated a trial before the Assembly of the Centuries. It is, however, possible that Gracchus rendered the plebeian assembly of the Tribes competent to