On the Origin of Sjpecies, 105 



clothed -when hatched. The shape and size of the eggs vary. The 

 manner of flight difl'ers remarkably ; as does in some breeds the 

 voice and disposition. Lastly, in certain breeds, the males and 

 females have come to differ to a slight degree from each other." 



" Altogether at least a score of pigeons might be chosen, which 

 if shown to an ornithologist, and he were told that they were wild 

 birds, would certainly, I think, be ranked by him as well-defined 

 species. Moreover, I do not believe that any ornithologist would 

 place the English carrier, the short-faced tumbler, the runt, the 

 barb, pouter, and fantail in the same genus ; more especially as 

 in each of these breeds several truly-inherited sub-breeds, or 

 species as he might have called them, could be shown him." 



" Great as the differences are between the breeds of pigeons, I am 

 fully convinced that the common opinion of naturalists is correct, 

 namely, that all have descended from the rock-pigeon (Columba 

 livia), including under this term several geographical races or 

 sub-species, which differ from each other in the most trifling re- 

 spects. As several of the reasons which have led me to this be- 

 lief are in some degree applicable in other cases, I will here 

 briefly give them. If the several breeds are not varieties, and 

 have not proceeded from the rock-pigeon, they must have des- 

 cended from at least seven or eight aboriginal stocks ; for it is 

 impossible to make the present domestic breeds by the crossing of 

 any lesser number : how, for instance, could a pouter be produc- 

 ed by crossing two breeds unless one of the parent-stock possessed 

 the characteristic enormous crop? The supposed aboriginal 

 stocks must all have been rock-pigeons, that is, not breeding or 

 willingly perching on trees. But besides C. livia, with its geo- 

 graphical sub-species, only two or three other species of rock- 

 pigeons are known ; and these have not any of the characters of 

 the domestic breeds. Hence the supposed aboriginal stocks must 

 either still exist in the countries where they were originally do- 

 mesticated, and yet be unknown to ornithologists ; and this, con- 

 sidering their size, habits, and remarkable characters, seems very 

 improbable; or they must have become extinct in the wild state. 

 But birds breeding on precipices, and good fliers, are unlikely to 

 be exterminated ; and the common rock-pigeon, which has the 

 same habits with the domestic breeds, has not been exterminated 

 even on several of the smaller British islets, or on the shores of 

 the Mediterranean. Hence the supposed extermination of so 

 many species having similar habits with the rock-pigeon seems to 



