THE POULTRY-YARD. 267 



self-defence. It gives early warning of the ap- 

 proach of any foe to the lapwing, and the latter 

 either beats off the enemy from the common 

 nesting - ground or entices him away by pre- 

 tending to be wounded. 



Some associations are of the slightest and 

 most temporary kind, as when a swallow skims 

 to and fro for a few hundred yards in front 

 of a rider for the sake of the insects disturbed 

 or attracted by the horse ; while others are so 

 binding that a dissolution would bring ruin to 

 both parties. It seems not at all unlikely that 

 the ancestors of our domestic pigeons, which 

 built their nests on the ledges and crevices 

 of the rocks, found the dwelling of some pre- 

 historic troglodyte a very efficient protection 

 against the raids of hawks and crows. Yet 

 although pigeons and certain other birds may 

 have become partially domesticated in this man- 

 ner, it seems hardly likely that savages — who are 

 generally keenly on the look out for something 

 to eat — would, either from sentiment or any other 

 motive, have allowed such birds as the duck or 

 the common fowl to nest in their neighbourhood 

 without molestation. Most probably such birds 

 as these were tamed in the same way as were 



