175 Scholiast on Aristophanes, _Knights_, 720; Suidas, _s.vv_. εἰρεσιώνη and προηροσίαι; _Etymologicum Magnum_, Hesychius, and Photius, _Lexicon_, _s.v._ προηρόσια; Plutarch, _Septem Sapientum Convivium_, 15; Dittenberger, _Sylloge Inscriptionum Graecarum_,2 No. 521, line 29, and No. 628; Aug. Mommsen, _Feste der Stadt Athen im Altertum_ (Leipsic, 1898), pp. 192 _sqq._ The inscriptions prove that the Proerosia was held at Eleusis and that it was distinct from the Great Mysteries, being mentioned separately from them. Some of the ancients accounted for the origin of the festival by a universal plague instead of a universal famine. But this version of the story no doubt arose from the common confusion between the similar Greek words for plague and famine (λοιμός and λιμός). That in the original version famine and not plague must have been alleged as the reason for instituting the Proerosia, appears plainly from the reference of the name to ploughing, from the dedication of the festival to Demeter, and from the offerings of first-fruits; for these circumstances, though quite appropriate to ceremonies designed to stay or avert dearth and famine, would be quite inappropriate in the case of a plague. M40 The _Proerosia_ seems to have been held before the ploughing in October but after the Great Mysteries in September. However, the date of the Great Mysteries, being determined by the lunar calendar, must have fluctuated in the solar year; whereas the date of the _Proerosia_, being determined by observation of Arcturus, must have been fixed. 176 Hesychius, _s.v._ προηρόσια. 177 August Mommsen, _Feste der Stadt Athen im Altertum_, p. 194. 178 August Mommsen, _l.c._ 179 Dittenberger, _Sylloge Inscriptionum Graecarum_,2 No. 521, lines 29 _sqq._ 180 Dittenberger, _Sylloge Inscriptionum Graecarum_,2 No. 628. 181 The view that the Festival before Ploughing (_Proerosia_) fell in Pyanepsion is accepted by W. Mannhardt and W. Dittenberger. See W. Mannhardt, _Antike Wald- und Feldkulte_ (Berlin, 1877), pp. 238 _sq._; _id._, _Mythologische Forschungen_, p. 258; Dittenberger, _Sylloge Inscriptionum Graecarum_,2 note 2 on Inscr. No. 628 (vol. ii. pp. 423 _sq._). The view that the Festival before Ploughing fell in Boedromion is maintained by August Mommsen. See his _Heortologie_ (Leipsic, 1864), pp. 218 _sqq._; _id._, _Feste der Stadt Athen im Altertum_ (Leipsic, 1898), pp. 192 _sqq._ 182 See below, p. 82. 183 L. Ideler, _Handbuch der mathematischen und technischen Chronologie_ (Berlin, 1825-1826), i. 292 _sq._; compare August Mommsen, _Chronologie_ (Leipsic, 1883), pp. 58 _sq._