ἀνάγκη τὸ κινοῦν ἀντικινεῖσθαι → what incites movement must suffer a counter-movement
perch: P. and V. καθῆσθαι, καθίζειν.
roost upon: Ar. ἐφέζεσθαι (dat.).
roost on a perch: Ar. ἐπὶ ξύλου καθεύδειν (Nubes 1431).
