40 ORIGIN OF SPECIES 



sessed the characteristic enormous crop ? The supposed abo- 

 riginal stocks must all have been rock-pigeons, that is, they 

 did not breed or willingly perch on trees. But besides C. 

 livia, with its geographical 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 domesticated, and yet 

 be unknown to ornithologists; and this, considering their 

 size, habits, and remarkable characters, seems 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 ex- 

 terminated 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 a very rash assumption. Moreover, 

 the several 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 become 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 ani- 

 mals 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 thor- 

 oughly domesticated in ancient times by half-civilised man, 

 as to be quite prolific under confinement. 



An argument of great weight, and applicable in several 

 other cases, is, that the above-specified breeds, though agree- 

 ing generally with the wild rock-pigeon in constitution, habits, 

 voice, colouring, 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 Columbidje for a beak like 

 that of the English carrier, or that of the short-faced tum- 

 bler, 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- 



