But cases of great difficulty, which I will not here enumerate, sometimes arise in deciding whether or not to rank one form as a variety of another, even when they are closely connected by intermediate links;
Baina zailtasun handiko kasu asko sortzen dira, nik hemen zerrendatuko ez ditudanak, forma bat bestearen aldakitzat sailkatu behar den ala ez erabakitzean, biak bitarteko lokarri hertsiz loturik daudenean ere;