246 ADVENTURES AMONG BIRDS 



vive to return to the same spot, one presently makes 

 himself master, and the other or others, driven away, 

 settle where they can, as near by as possible. It is 

 probably harder for the nightingale to go a mile away 

 from his true home, the very spot where he was hatched 

 and reared, than to fly away thousands of miles to his 

 wintering place in the autumn. The bird is exceed- 

 ingly reluctant to leave his home, but if the annual in- 

 crease was greater, a third greater let us say, more and 

 more birds would be compelled to go further afield. 

 They would go slowly, clinging to unsuitable places near 

 their cradle-home rather than go far, but the continual 

 pressure would tell in the end; the best places within 

 the nightingale country, the ten thousand oak and hazel 

 copses and thickets which are now untenanted, would 

 be gradually occupied, and eventually the limits would 

 be enlarged. That they cannot be extended artificially 

 we know from the experiments in Scotland of Sir John 

 Sinclair and of others in the north of England, who 

 procured nightingales' eggs and had them placed in 

 robins' nests. The young were hatched and safely 

 reared, and, as was expected, disappeared in the autumn, 

 but they never returned. We can only assume that the 

 "inherited memory" of its true home, which was not 

 Scotland nor Yorkshire, but where the egg was laid, 

 was in every bird's brain from the shell, that if it ever 

 survived to return from its far journey it came faith- 

 fully back to the very spot where the egg had been taken. 

 That man's persecution tells seriously on the species 

 may be seen from what has happened on the Continent, 



