18 THE ORIGIN OF SPECIES 



above-named domesticated breeds have been transported to all 

 parts of the world, and, therefore, some of them must have been 

 carried back again into their native country; but not one has be- 

 come wild or feral, though the dovecot-pigeon, which is the rock- 

 pigeon in a very slightly altered state, has become feral in several 

 places. Again, all recent experience shows that it is difficult to get 

 wild animals to breed freely under domestication; yet on the hy- 

 pothesis of the multiple origin of our pigeons, it must be assumed 

 that at least seven or eight species were so thoroughly domesti- 

 cated in ancient times by half -civilized man as to be quite prolific 

 under confinement. 



An argument or great weight, and applicable in several other 

 cases, is, that the above-specified breeds, though agreeing gener- 

 ally with the wild rock-pigeon in constitution, habits, voice, color- 

 ing, and in most parts of their structure, yet are certainly highly 

 abnormal in other parts; we may look in vain through the whole 

 great family of Columbidae for a beak like that of the English car- 

 rier, or that of the short- faced tumbler, or barb; for reversed 

 feathers like those of the Jacobin; for a crop like that of the 

 pouter; for tail-feathers like those of the fantail. Hence it must 

 be assumed, not only that half-civilized man succeeded in thor- 

 oughly domesticating several species, but that he intentionally or 

 by chance picked out extraordinarily abnormal species; and fur- 

 ther, that these very species have since all become extinct or un- 

 known. So many strange contingencies are improbable in the 

 highest degree. 



Some facts in regard to the coloring of pigeons well deserve con- 

 sideration. The rock-pigeon is of a slaty-blue, with white loins; 

 but the Indian sub-species, C. intermedia of Strickland, has this 

 part bluish. The tail has a terminal dark bar, with the outer feath- 

 ers externally edged at the base with white. The wings have two 

 black bars. Some semi-domestic breeds, and some truly wild 

 breeds, have, besides the two black bars, the wings checkered 

 with black. These several marks do not occur together in any 

 other species of the whole family. Now, in every one of the do- 

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

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

 times concur perfectly developed. Moreover, when birds belong- 

 ing to two or more distinct breeds are crossed, none of which are 

 blue or have any of the above-specified marks, the mongrel off- 

 spring are very apt suddenly to acquire these characters. To give 

 one instance out of several which I have observed: I crossed some 

 white fantails, which breed very true, with some black barbs — 



