THE PIGEON FAMILY • 93 



a character, or quality, inherent in some animals 

 and entirely wanting in others. 



Let us begin with pigeons, a very large group, 

 but one that shows more unity than any of the other 

 Orders into which naturalists divide birds. It 

 embraces turtle doves of many species, wood 

 pigeons, ground pigeons, fruit pigeons and some 

 strange forms like the great crowned pigeon of 

 Victoria. Of all these only one, the common blue 

 rock, has been domesticated. The ring dove of 

 Asia has been kept as a cage bird for so long that a 

 permanent albino and also a fawn-coloured variety 

 have been established and are more common in 

 aviaries than birds of the natural colour ; but the 

 ring dove has not become a domestic fowl, and never 

 will. In this instance there is a plausible explana- 

 tion, for the blue rock, unlike the rest of the tribe, 

 nests and roosts in holes and is also gregarious ; 

 therefore, if provided with accommodation of the 

 kind it requires, it will form a permanent settlement 

 and remain with us on the same terms as the honey 

 bee ; while the ring dove, not caring for a fixed home, 

 must be confined, however tame it may become, or 

 it will wander and be lost. 



But this explanation will not fit other cases. 

 What a multitude of wild ducks there are in Scotland 

 and every other country, mallards, pintails, gad- 

 walls, widgeons, pochards and teals, all very much 

 alike in their habits and tastes ! But of them all 

 only one species, and that a migratory one, the 



