BRITAIN'S BIRDS AND THEIR NESTS. 75 



migrate with the rest — being replaced by birds from the 

 extreme north of the range — but return earlier than those 

 which must nest in countries remaining longer in the grip 

 of winter ? If that were so, would not the flocks about 

 our coasts, which we have for the moment assumed to 

 breed farther north than any wintering to the south of 

 us, be the very last to go ? After all, the first sug- 

 gestion seems the more likely, but proof is entirely lacking. 

 Nor is it easy to imagine any possible method of proof 

 except, perhaps, bird-marking on an immense scale. The 

 question is no mere matter of interesting speculation, but 

 one which, unanswered, obstructs the threshold of the great 

 problem of the origin of the migrational habit, which in 

 turn leads us to deep problems of psychology, heredity, 

 and other aspects of biology as far-reaching and important 

 as they are intricate and difficult. 



The Golden Plover, or simply the ' Plover, ^ for it is 

 the typical species, is a truly handsome bird in its summer 

 dress, with the deep-black under-parts, the pure white on 

 head and flanks, and the mottled greenish yellow of the 

 upper plumage. On a museum shelf it stands conspicuous 

 among the sober hues of the Sandpipers and Snipe that 

 may be placed beside it. But on the open moor it is 

 found to be as protectively coloured as any. 



A rough Highland road winds across a vista of rolling 

 moorland, not purple yet, but brown and green, relieved 

 occasionally by clumps of the hardier flowers of early 

 summer. As we follow it our attention is held in turn 

 by the dark-blue, massive hills, cloud-capped and patched 

 with lingering snow, and by the cold, gray, wind- 

 whipped loch in the hollow, with its island ruin, its 

 issuing torrent of foamy, peat-brown water, and its 

 drinking herd of shaggy, long-horned cattle or wild red- 

 deer. A cry overhead suddenly recalls us to oui' nearer 



