Notes: The EC-WC comparison belongs to Trubetzkoy (1930, 278). Except for the loss of labialisation (which sometimes happens in verbal WC roots - possibly because of interaction with class prefixes) correspondences are regular, and the etymology seems plausible. Some forms (Av. orč̣-, PN *=erc̣-) reflect a variant with infixed (probably durative) *-r-; one can also compare Urart. erc̣- 'to return' (see Diakonoff-Starostin 1986, 45).