Chap. VI. THEIR PAKENTAGE. 189 



varieties, may be admitted as almost certain. On the doctrine, 

 therefore, that the chief races owe their differences to their 

 descent from distinct species, we must admit that at least eight 

 or nine, or more probably a dozen species, all having the same 

 habit of breeding and roosting on rocks and living in society, 

 either now exist somewhere, or formerly existed but have 

 become extinct as wild birds. Considering how carefully wild 

 pigeons have been collected throughout the world, and what 

 conspicuous birds they are, especially when frequenting rocks, 

 it is extremely improbable that eight or nine species, which were 

 long ago domesticated and therefore must have inhabited some 

 anciently known country, should still exist in the wild state 

 and be unknown to ornithologists. 



The hypothesis that such species formerly existed, but have 

 become extinct, is in some slight degree more probable. But 

 the extinction of so many species within the historical period is 

 a bold hypothesis, seeing how little influence man has had in 

 exterminating the common rock-pigeon, which agrees in all its 

 habits of life with the domestic races. The C. livia now exists 

 and flourishes on the small northern islands of Faroe, on many 

 islands off the coast of Scotland, on Sardinia, and the shores of 

 the Mediterranean, and in the centre of India. Fanciers have 

 sometimes imagined that the several supposed parent-species 

 were originally confined to small islands, and thus might 

 readily have been exterminated ; but the facts just given do not 

 favour the probability of their extinction, even on small islands. 

 Nor is it probable, from what is known of the distribution of 

 birds, that the islands near Europe should have been inhabited 

 by peculiar species of pigeons ; and if we assume that distant 

 oceanic islands were the homes of the supposed parent-species, 

 we must remember that ancient voyages were tediously slow, 

 and that ships were then ill-provided with fresh food, so that 

 it would not have been easy to bring home living birds. 

 I have said ancient voyages, for nearly all the races of the 

 pigeon were known before the year 1600, so that the supposed 

 wild species must have been captured and domesticated before 

 that date. 



Secondly.— The doctrine that the chief domestic races have 

 descended from several aboriginal species, implies that several 



