Chap. I. 
DOMESTIC PIGEONS. 
23 
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 respects. As 
several of the reasons which have led me to this belief 
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 descended 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 produced by crossing two 
breeds unless one of the parent-stocks 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 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 domes¬ 
ticated, and yet be unknown to ornithologists; and this, 
considering their size, habits, and remarkable characters, 
seems very improbable; or they must have become 
extinct in the wild state. But birds breeding on preci¬ 
pices, 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 
