Since no Eastern Dag. reflexes are attested, one can also reconstruct initial *Hr-. The Ub. form may be theoretically compared also with PEC *darq̇wV q.v.; we prefer, however, to compare it with PEC *rĭŁ_wV (thus arriving at the PNC reconstruction *rĭg_wĂ), because it matches exactly (both semantically and phonetically) PN *daχḳa 'mouse'. The comparison of PN and Ub. forms was first proposed by Trubetzkoy (1930, 277). See also Abdokov 1983, 120-121 (although with a great deal of confusion between several NC roots). The Kartvelian material (PK *(ś)tagw- 'mouse'), linked with this root by Bork (1907, 27) and Klimov (1963, 175) may belong here as a loan from some EC source (or else it may be compared with PEC *darq̇wV q.v.).