Chap. I. DOMESTIC PIGEONS. 25 



Some facts in regard to the colouring of pigeons 

 well deserve consideration. The rock-pigeon is of a 

 slaty-blue, and has a white rump (the Indian sub- 

 species, C. intermedia of Strickland, having it bluish) ; 

 the tail has a terminal dark bar, with the bases of the 

 outer feathers externally edged with white ; the wings 

 have two black bars; some semi-domestic breeds and 

 some apparently truly wild breeds have, besides the 

 two black bars, the wings chequered with black. These 

 several marks do not occur together in any other species 

 of the whole family. Now, in every one of the domestic 

 breeds, taking thoroughly well-bred birds, all the above 

 marks, even to the white edging of the outer tail- 

 feathers, sometimes concur perfectly developed. More- 

 over, when two birds belonging to two distinct breeds 

 are crossed, neither of which is blue or has any of the 

 above-specified marks, the mongrel offspring are very 

 apt suddenly to acquire these characters ; for instance, 

 I crossed some uniformly white fantails with some 

 uniformly black barbs, and they produced mottled 

 brown and black birds ; these I again crossed together, 

 and one grandchild of the pure white fantail and pure 

 black barb was of as beautiful a blue colour, with the 

 white rump, double black wing-bar, and barred and 

 white-edged tail-feathers, as any wild rock-pigeon ! We 

 can understand these facts, on the well-known principle 

 of reversion to ancestral characters, if all the domestic 

 breeds have descended from the rock-pigeon. But if 

 we deny this, we must make one of the two following 

 highly improbable suppositions. Either, firstly, that all 

 the several imagined aboriginal stocks were coloured 

 and marked like the rock-pigeon, although no other 

 existing species is thus coloured and marked, so that in 

 each separate breed there might be a tendency to revert 

 to the very same colours and markings. Or, secondly, 



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