Many of the cases of strongly marked varieties or doubtful species well deserve consideration; for several interesting lines of argument, from geographical distribution, analogical variation, hybridism, etc., have been brought to bear in the attempt to determine their rank;
Aldaki oso markatu edo dudazko espezieen kasu askok hausnarketa merezi du benetan; izan ere, mota ezberdineko arrazoiak jarri izan dira, geografi banaketa, aldakuntza analogiko, hibridismo eta abarretan oinarrituz, haien kategoria erabakitzen saiatzeko;