232 DOMESTIC PIGEONS. Chap. VI. 



were closely allied to Carriers and Barbs, but which competent 

 authorities cannot now identify with our present Barbs and 

 Carriers ; nor can Aldrovandi's Runts be identified with our 

 present Runts. These four breeds certainly did not differ 

 from each other nearly so much as do our existing English 

 Carriers, Barbs, and Runts. All this is exactly what might 

 have been anticipated. If we could collect all the pigeons 

 which have ever lived, from before the time of the Romans 

 to the present day, we should be able to group them in 

 several lines, diverging from the parent rock-pigeon. Each 

 line would consist of almost insensible steps, occasionally 

 broken by some slightly greater variation or sport, and each 

 would culminate in one of our present highly modified forms. 

 Of the many former connecting links, some would be found 

 to have become absolutely extinct without having left any 

 issue, whilst others, though extinct, would be recognized as 

 the progenitors of the existing races. 



I have heard it remarked as a strange circumstance that 

 we occasionally hear of the local or complete extinction of 

 domestic races, whilst we hear nothing of their origin. How, 

 it has been asked, can these losses be compensated, and more 

 than compensated, for we know that with almost all domes- 

 ticated animals the races have largely increased in number 

 since the time of the Romans ? But on the view here given, 

 we can understand this apparent contradiction. The ex- 

 tinction of a race within historical times is an event likely 

 to be noticed ; but its gradual and scarcely sensible modifi- 

 cation through unconscious selection, and its subsequent 

 divergence, either in the same or more commonly in distant 

 countries, into two or more strains, and their gradual conver- 

 sion into sub-breeds, and these into well-marked breeds are 

 events which would rarely be noticed. The death of a tree, 

 that has attained gigantic dimensions, is recorded ; the slow 

 growth of smaller trees and their increase in number excite 

 no attention. 



In accordance with the belief in the great power of selection, 

 and of the little direct power of changed conditions of life, 

 except in causing general variability or plasticity of organisa- 

 tion, it is not surprising that dovecot-pigeons have remained 



