As the contio did not, like the comitia, theoretically include all the people, any number of magistrates could simultaneously hold meetings of the kind.[787] A minor officer had no right to take charge of, or to summon the people from, a contio called by another. A higher officer exercised this right against a lower; the consul, for instance, could take the meeting from the hands of any ordinary patrician magistrate,[788] though not of a tribune of the plebs. No one dared disturb a meeting of any kind under the presidency of the latter,[789] and at least in the late republic a tribune sometimes forbade a patrician magistrate to address an assembly;[790] but otherwise consuls and plebeian tribunes might hold simultaneous contiones.[791] Sometimes the contio was summoned merely to witness a public act. The consuls called the people together outside the walls by the sound of the war-trumpet to see an execution for treason. On this occasion the citizens were arrayed in centuries on the Campus Martius, in an assembly called at once comitia centuriata and contio.[792] We hear of a similar execution of an astrologer or magician outside the Esquiline gate, according to a primitive custom;[793] and it was most probably in a contio that the supreme pontiff scourged to death a man who had wronged a Vestal.[794] The people gathered in the same kind of meeting to witness an oath,[795] a judicial process,[796] or the levy of a fine.[797] But it was preëminently the listening assembly, hence the definition offered by Gellius,[798] “To hold a contio is to address the people, without calling on them for a vote.” It applied not only to the isolated meeting summoned to hear edicts, reports, communications of every kind, including arguments and appeals for or against a given policy,[799] but also to the preparatory stage of the voting assembly whether addresses were delivered or not. Occasionally in early times there was speaking on the merits of candidates at the opening of an electoral assembly, and the voting was sometimes interrupted for the purpose.[800] Before the age of Cicero this rare proceeding had disappeared. In his day the canvass for candidates had been made before the holding of the preliminary contio, which accordingly was brief and formal. Because much time was required for the voting of the centuries,[801] speaking on the day of their assembly had to be minimized. For this reason the contio for advising the adoption of a resolution by the comitia centuriata was held on an earlier day. Such was the meeting summoned in the Campus Martius by the consul P. Lentulus for the purpose of urging the people to vote in the ensuing centuriate assembly for the recall of Cicero.[802] In judicial proceedings before any of the assemblies the testimonies of witnesses and the pleadings occupied the greater part of the time, and for this reason judicial assemblies were frequently termed simply contiones. They will be described in a later chapter.[803]