Works dealing with the subject: Bruno Keil, _Die Solonische Verfassung nach Aristoteles_ (Berlin, 1892); G. Gilbert, _Constitutional Antiquities of Sparta and Athens_ (Eng. trans., 1895); U. von Wilamowitz-Moellendorff, _Aristoteles und Athen_ (2 vols., Berlin, 1893), a work of great importance, in spite of many unsound conclusions; E. Meyer, _Forschungen_, vol. ii. pp. 406 ff. (the section dealing with the Four Hundred is especially valuable). Articles: R. W. Macan, _Journal of Hellenic Studies_ (April 1891); R. Nissen, _Rheinisches Museum_ (1892), p. 161; G. Busolt, _Hermes_ (1898), pp. 71 ff.; O. Seeck, "Quellenstudien zu des Aristoteles' Verfassungsgeschichte Athens," in Lehmann's _Beitraege zur alten Geschichte_, vol. iv. pp. 164 and 270. (E. M. W.) CONSUETUDINARY (Med. Lat. _consuetudinarius_, from _consuetudo_, custom), customary, a term used especially of law based on custom as opposed to statutory or written law. As a noun "consuetudinary" (Lat. _consuetudinarius_, sc. _liber_) is the name given to a ritual book containing the forms and ceremonies used in the services of a particular monastery, cathedral or religious order. CONSUL (in Gr. generally [Greek: hypatos], a shortened form of [Greek: strategos hypatos], i.e. _praetor maximus_), the title borne by the two highest of the ordinary magistrates of the whole Roman community during the republic. In the imperial period these magistrates had ceased practically to be the heads of the state, but their technical position remained unaltered. (For the modern commercial office of consul see the separate article below.)