Most of our domesticated animals have run wild in various parts of the world; but birds, owing apparently to their partial loss of the power of flight, less often than quadrupeds. Nevertheless I have met with accounts showing that the common fowl has become feral in South America and perhaps in West Africa, and on several islands: the turkey was at one time almost feral on the banks of the Parana; and the Guinea-fowl has become perfectly wild at Ascension and in Jamaica. In this latter island the peacock, also, "has become a maroon bird." The common duck wanders from its home and becomes almost wild in Norfolk. Hybrids between the common and musk-duck which have become wild have been shot in North America, Belgium, and near the Caspian Sea. The goose is said to have run wild in La Plata. The common dovecote-pigeon has become wild at Juan Fernandez, Norfolk Island, Ascension, probably at Madeira, on the shores of Scotland, and, as is asserted, on the banks of the Hudson in North America. (6/18. With respect to feral pigeons--for Juan Fernandez see Bertero in 'Annal. des Sc. Nat.' tome 21 page 351. For Norfolk Islands see Rev. E.S. Dixon in the 'Dovecote' 1851 page 14 on the authority of Mr. Gould. For Ascension I rely on MS. information given me by Mr. Layard. For the banks of the Hudson, see Blyth in 'Annals of Nat. Hist.' volume 20 1857 page 511. For Scotland see Macgillivray 'British Birds' volume 1 page 275; also Thompson 'Nat. Hist. of Ireland, Birds' volume 2 page 11. For ducks see Rev. E.S. Dixon 'Ornamental Poultry' 1847 page 122. For the feral hybrids of the common and musk-ducks see Audubon 'American Ornithology' and Selys-Longchamp 'Hybrides dans la Famille des Anatides.' For the goose Isidore Geoffroy St.-Hilaire 'Hist. Nat. Gen.' tome 3 page 498. For guinea-fowls see Gosse 'Naturalist's Sojourn in Jamaica' page 124; and his 'Birds of Jamaica' for fuller particulars. I saw the wild guinea-fowl in Ascension. For the peacock see 'A Week at Port Royal' by a competent authority, Mr. R. Hill, page 42. For the turkey I rely on oral information; I ascertained that they were not Curassows. With respect to fowls I will give the references in the next chapter.) But how different is the case, when we turn to the eleven chief domestic races of the pigeon, which are supposed by some authors to be descended from so many distinct species! no one has ever pretended that any one of these races has been found wild in any quarter of the world; yet they have been transported to all countries, and some of them must have been carried back to their native homes. On the view that all the races are the product of variation, we can understand why they have not become feral, for the great amount of modification which they have undergone shows how long and how thoroughly they have been domesticated; and this would unfit them for a wild life. FOURTHLY.