Although, after the _provocatio_ had limited the right of inflicting death and scourging, the means of _coercitio_ were much the same for every magistrate, a formal difference in its mode of exercise existed between the higher and lower magistrates, and between the magistrates with _imperium_ and the tribunes. The consuls and other magistrates with _imperium_ had the right of summoning delinquents before their tribunal (_vocatio_) as well as of summarily arresting them in person (_prensio_).[727] The quaestors and lower officials had neither of these rights; and the theory of the tribune’s being an exceptional magistrate who should render assistance in person[728] was so far preserved that he had only the right of arrest.[729] We sometimes meet with tribunes who carried out their mandates with their own hands, but their presence alone was sufficient for the _prensio_ to be effective; in early times they used their aediles for the act of violence, in later times their _viatores_.[730] By the close of the Republic the distinction was obliterated, and the tribunes, without formal right, summoned individuals before them.[731] A mere enumeration of the powers of the Roman magistracy throws little light on the working of the civic constitution. The question which we shall now consider—the conflict of powers—is from this point of view more instructive if only because it shows why Rome could not be governed by her magistrates. The first ground of conflict was religious and arose from a use, or rather misuse, of the auspices, which we have hitherto refrained from discussing because it is only indirectly connected with the _jus auspiciorum_. It arose from a power possessed not by the magistrate only but by every Roman citizen. It was the duty of any one who was the witness of an evil omen (e.g. one of the _dirae_ belonging to the class of _auspicia oblativa_) to give notice of this occurrence to any magistrate about to embark on an important undertaking. The most frequent occasion on which such _obnuntiatio_[732] was employed was the holding of the _comitia_. The respect paid to this announcement by the magistrate guiding the proceedings naturally depended on the position which the announcer held in the state. The notice of a private and unknown citizen might be received with suspicion; that given by an augur, who actually waited by the _comitia_ to watch for such signs,[733] or by another magistrate, would usually be respected. But, while the _obnuntiatio_ of the augur, the plebeian magistrate, and the private citizen depended on chance, that of the patrician magistrate could be the result of design. Observation of the heavens was, as we saw, the favourite form of _spectio_ of the urban magistrate, and the belief was strongly held that, if he asked a sign, the sign would come. The lightning which appeared might be a lucky or unlucky omen for the magistrate himself; but, whether it appeared on the left or right, it was, as an _auspicium oblativum_,