Chap. VI. THEIR PARENTAGE. 193 



spot on the two sides, but chiefly on the outer side, of each feather. 

 The wing-bars in the true rock-pigeon and in the chequered 

 variety are, in fact, due to similar though larger spots symmetrically 

 crossing the secondary wing-feather and the larger coverts. Hence 

 the chequering arises merely from an extension of these marks to 

 other parts of the plumage. Chequered birds are not confined to 

 the coasts of England ; for they were found by Graba at Faroe ; and 

 W. Thompson 12 says that at Islay fully half the wild rock-pigeons 

 were chequered. Colonel King, of Hythe, stocked his dovecot with 

 young wild birds which he himself procured from nests at the 

 Orkney Islands ; and several specimens, kindly sent to me by him, 

 were all plainly chequered. As we thus see that chequered birds 

 occur mingled with the true rock-pigeon at three distinct sites, 

 namely, Faroe, the Orkney Islands, and Islay, no importance can 

 be attached to this natural variation in the plumage. 



Prince C. L. Bonaparte, 13 a great divider of species, enumerates, 

 with a mark of interrogation, as distinct from ft livla, the O. turrico a 

 of Italy, the ft rupestris of Daouria, and the ft. schimperi of Abys- 

 sinia ; but these birds differ from ft. livla in characters of the most 

 trifling value. In the British Museum there is a chequered pigeon, 

 probably the ft. schimperi of Bonaparte, from Abyssinia. To these 

 may be added the ft gymnocyclus of G. E. Gray from W. Africa, 

 which is slightly more distinct, and has rather more naked skin 

 round the eyes than the rock-pigeon ; but from information given 

 me by Dr. Daniell, it is doubtful whether this is a wild bird, for 

 dovecot-pigeons (which I have examined) are kept on the coast of 

 Guinea. 



The wild rock-pigeon of India (ft. intermedia of Strickland) has 

 been more generally accepted as a distinct species. It differs chiefly 

 in the croup being blue instead of snow-white ; but as Mr. Blyth 

 informs me, the tint varies, being sometimes albescent. "When this 

 form is domesticated chequered birds appear, just as occurs in 

 Europe with the truly wild ft. livia. Moreover we shall immediately 

 have proof that the blue and white croup is a highly variable 

 character ; and Bechstein 14 asserts that with dovecot-pigeons in 

 Germany this is the most variable of all the characters of the 

 plumage. Hence it may be concluded that ft intermedia cannot be 

 ranked as specifically distinct from ft livia. 



In Madeira there is a rock-pigeon which a few ornithologists have 

 suspected to be distinct from ft. livia. I have examined numerous 

 specimens collected by Mr. E. V. Harcourt and Mr. Mason. They 

 are rather smaller than the rock-pigeon from the Shetland Islands, 

 and their beaks are plainly thinner, but the thickness of the beak 

 varied in the several specimens. In plumage there is remarkable 



12 'Natural History of Ireland,' geons,' * Comptes Rendus,' 1854— 55. 

 Birds, vol. ii. (1850), p. 11. For 14 ' Naturgeschichte. DeutschlaacU, 



Graba, see previous reference. Band iv. 1795, s. 14. 



1J 'Coup-d'ceil sur l'Ordre des Pi- 



