226 STUDIES IN BIRD-MIGRATION 



menon of birds proceeding westward and northward 

 from their breeding grounds to reach their winter 

 quarters, and this in vast numbers for several successive 

 weeks, with scarcely a break, except those imposed by 

 unfavourable weather. In some seasons this immigra- 

 tion — along what may be called especially the Skylarks' 

 route, since they greatly outnumber the birds of any 

 other species using it ■ — sets in as early as the 

 middle of September, but more commonly about the 

 fourth week of that month. It is in October, however, 

 that this stream of immigration becomes phenomenal. 

 Some idea of the magnitude of this influx may be 

 gathered from this table, showing the number of days 

 during October on which it was observed in each of the 

 years : — 



This stream has the coast of Essex and the mouth of 

 the Thames for its centre, with its right wing extending 

 to the Humber, or even beyond ; while the left sweeps 

 south-west towards the Kentish littoral, and then along 

 the south coast to Devon and Cornwall, some of the 

 migrants crossing the Channel at various points to the 

 French shores, while others continue westward and north- 

 ward to Ireland, and appear on the coast of co. Wex- 

 ford. The winter visitants to England, which are very 

 many, among these immigrants, pass inland by several 

 routes (numbers by way of the Thames and Humber 

 estuaries), and disperse themselves over the eastern, 



' Many recorded on 9th, 20th, 21st, 23rd, and 27th October ; vast numbers 

 on i6th to i8th, again on 22nd, 25tli, and 26th October. 



