242 THE MIGRATION OF BIRDS. 



the British Islands, it will be necessary to recapit- 

 ulate at least a portion of our earlier chapters. The 

 lirst portion of the subject on which it becomes 

 necessary to dwell is that of Routes. Undoubtedly 

 the most important Highways of Migration in the 

 British Islands are along the coast-lines. This is 

 very forcibly expressed by Mr. Cordeaux : "An 

 observer taking up his position at a short distance 

 from the coast would see or know nothing of 

 Migration, yet within half a mile or less there might 

 be a constant stream of birds, hour by hour, and day 

 by day, passing to the south." This is probably owing 

 to the small area of the islands, and the coast-lines 

 trending almost entirely from north to south — a 

 direction favouring passage not only for species 

 breeding or wintering in this locality, but for those 

 birds that pass along them during spring and 

 autumn flight. Undoubtedly the most important 

 of these extend along the east and south coasts, 

 and drain a considerable migration from Scandinavia 

 by way of the Shetlands and Orkneys. At the 

 latter, the route seems to branch into two, one 

 following the west coast of Scotland, including the 

 Hebrides, to the north of Ireland, where another 

 branch occurs, the western following the Atlantic 

 seaboard (a route little traversed by Passerine 

 birds) ; the eastern, the coasts of St. George's 

 Channel, the Irish Sea, and the Bristol Channel, 

 along which highway great numbers of small birds 

 pass from the south, and vice versa. These Routes 

 may be roughly taken as the general direction of 



