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, 0. 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, 
c 
