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16th, S.E., and later, N.B., four or five. Spurn, September 15tli, 

 two seen, one shot ; 18th, three shot and others seen. Isle of 

 Thanet, September 13th, two seen. . . . Heligoland, August 

 31st, some young ; September 1st and 3rd, pretty numerous ; 9th 

 and 19th, very many ; 11th and 12th, very great numbers, and 

 less to 18th, 19th and 20th. They were thus most numerous at 

 the latter locality at the same time as the largest flock was 

 observed in Norfolk. Commenting on this immigration of Blue- 

 throats to the Norfolk coast Mr. J. H. Gurney remarks : — " It 

 would seem that the Bluethroats came in just the sort of com- 

 pany they might have been expected in, viz., with Tree Pipits, 

 Wheatears, Yellow Wagtails, and Greater Whitethroats, and 

 this company probably arrived with a light wind from the north. 

 On September 13th, the day before they were noticed, the wind 

 was light N. ; on the 12th it was light N.B., or E.N.E., and on 

 the 11th it was N.N.E. ; on the 17th the wind was N.B., and they 

 probably left Blakeney, and migrating against it, got as far as 

 Yarmouth and Lowestoft ' denes.' On the 18th it was S., and 

 pursuing the coast southwards they most likely crossed the 

 Channel. . . . The two birds shot by Mr. Power on the 22nd 

 at Blakeney were I imagine, a later arrival, and if, as is most 

 probable, they came on the previous day, it was with a west 

 wind, i.e., a contrary wind. On the same day a Bluethroat 

 was shot on the coast of Northumberland, as I learn from Mr. 

 T. H. Archer, and the day before one was identified, but not shot, 

 at Tees mouth." Then follows an interesting foot-note in which 

 Mr. Gurney quotes Mr. John Cordeaux, to the effect that " it 

 may be laid down as an axiom that, with southerly or westerly 

 winds, not amounting to gales, normal migration to our east 

 coast in autumn is the ruie (see ' Eeport on Migration,' 1881, 

 p. 39). No wind at all suits small birds best. It seems, when 

 bent on migration, they will make the passage with a light cross 

 wind, but very rarely indeed with a wind which is due in their 

 favour." The opinions of two such experienced observers as Mr. 

 Cordeaux and Mr. J. H. Gurney will naturally be held in great 

 respect, but it will be seen that they are in conflict with that of 

 Herr Gatke, who states that on the prevalence of light E. winds, 

 i.e., winds due in the favour of birds, migration across Heligo- 



