Note 30 — Chapter VI · PIGEONS—continued.
Reading edition
It deserves notice, as bearing on the general subject of variation, that not only C. livia presents several wild forms, regarded by some naturalists as species and by others as sub-species or as mere varieties, but that the species of several allied genera are in the same predicament. This is the case, as Mr. Blyth has remarked to me, with Treron, Palumbus, and Turtur.