James Adam, The Republic of Plato

ἐρῶ. I have removed the colon after ἐρῶ on Richards' suggestion.

ὥσπερ ὀνείρατα -- αὐτούς: lit. ‘all these things which they fancied themselves suffering and happening to them were so to speak dreams.’ ἐδόκουν is ‘imagined’ as in Aesch. Pers. 188 (also of a dream) and elsewhere. The object of πάσχειν, viz. ταῦτα πάντα, becomes the subject of γίγνεσθαι: cf. (for the change of subject) Ap. 40 A, Symp. 200 D and supra I 333 C, II 359 D, E, 360 A. It must be allowed that the effect of this idiom is here unusually harsh. I once conjectured ὑπάρχειν for πάσχειν, taking ἐδόκουν still as ‘fancied’: but the text is probably sound.

ὑπὸ γῆς κτλ. Herwerden bids us bracket either ὑπό or ἐντός: but Plato rarely if ever lets the preposition ἐντός follow its noun. ὑπό is ‘under,’ not ‘by’ (it is ὁ θεός, not ἡ γῆ, who πλάττει, infra 415 A), and ἐντός is adverbial; “drinnen unter der Erde” (Schneider). Mortal creatures are similarly moulded within the earth in Protagoras' prehistoric myth (τυποῦσιν αὐτὰ θεοὶ γῆς ἔνδον 320 D): cf. also Symp. 191 C, Pol. 272 A, Tim. 42 D. The myth of the Politicus (269 A ff.) connects the autochthonous origin of man with the golden age, in agreement with a wide-spread tradition, which gave rise to a considerable literature (Dümmler Proleg. zu Platons Staat p. 46). It is in the spirit of this tradition that Plato here represents the first generation of his ideal city as autochthonous.