144 OUR RARER BIRDS 



seen in flocks, and may sometimes be observed feeding with 

 Thrushes and Finches. It occasionally visits the rocky beach 

 and the rough ground near the sea to feed on the seeds of 

 weeds. The food of the Kock Dove is chiefly composed of 

 grain and seeds of all kinds, which it picks up from the lands 

 and pastures near the sea, as well as on the sloping cliffs. 

 This bird is a voracious eater, and takes great quantities of 

 grain from the newly-sown land, as well as from the corn- 

 fields and stubbles. It also eats the buds and shoots of 

 herbage. 



It is worthy of remark that the Eock Dove is one of the 

 most constant of birds in the colour of its plumage — varieties 

 in a wild state being practically unknown ; but under the in- 

 fluences of domestication it varies in a most curious manner, 

 both in size and form and colour, and even in several parts 

 of its structure. It is one of the most wonderful instances of 

 the prodigality of ISTature in producing endless variations of 

 form and colour as soon as the checks to those variations are 

 removed. The Eock Dove's economy demands a certain 

 uniform standard of colour, of structure, and of form, which is 

 in harmony with" its ways of life in every respect, and up to 

 which it is rigorously kept by Natural Selection. But let 

 this check be once removed, and variation in many directions 

 asserts itself, and the inevitable result is what we now see in 

 the dovecots of civilised man — an almost endless variety of 

 Doves, all sprung from their common ancestor, the Eock 

 Dove, and all with a more or less strong tendency to revert 

 to the colour of the original stock if suitable conditions arise. 



