156 THE MIGRATIOX OF BRITISH BIRDS 



much more compact and continuous in the north (the 

 point of egress) than it is now in the south. On the 

 other hand, there is much evidence to suggest that the 

 stream of Coasting Migrants across the Irish Area is 

 much less in volume than the stream that passes over 

 Scotland and England, which must be due in a great 

 measure to the wide water areas south of Ireland. Many 

 instances, moreover, might be given in which a number 

 of individuals of certain species, which pass Scotland 

 and England only on migration, spend the winter in the 

 south of Ireland, as though their southern progress was 

 arrested by the impassable barrier of the open Atlantic 

 Ocean. Thus many Knots, Greenshanks, Gray Plovers, 

 Bar-tailed Godwits, and Short-eared Owls pass the 

 winter in Ireland ; whilst even such typical summer 

 migrants as the Blackcap Warbler and the Land Rail, 

 for instance, are frequently known to do so in the south 

 of that island — Coasting Migrants from the north which 

 have apparently gone too far west, and whose southern 

 flight has been abnormally arrested by the wide area of 

 unknown sea. We often hear of similar phenomena in 

 the south-west of England, where the sea-passage to the 

 Continent is very wide. I am not disposed to consider 

 such instances as due to the milder climate of these 

 areas tempting a winter sojourn : the individual birds in 

 question arc lost migrants, too far west of their normal 

 route. 



The Summer Migrants represent the species that were 

 the last to extend their breeding range northwards across 

 the British Area — then a portion of continental land. As 

 many of these birds reached the British Islands, wc have 

 every reason to believe that submergence had com- 



