139 



By what precise route these American species reach our 

 shores it is impossible to say, but from the fact that the majority 

 have been obtained on our eastern and southern coasts it is 

 most probable that they have travelled down the shores of 

 Norway and then crossed the North Sea, in company with our 

 customary visitors ; or they may, as Professor Newton points 

 out, have actually crossed the Atlantic with the aid of a strong 

 westerly gale. However, Herr Gatke will not admit the assist- 

 ance of the latter agency as at all necessary. The voyage across 

 the Atlantic according to his theory is undertaken as a voluntary 

 act, for he writes that the objection on the part of birds to 

 migrate east in the autumn; which according to his view is 

 apparent in Western Europe, ceases as soon as we cross the 

 Atlantic. Yet after discussing the question of the route by 

 which American species reach Heligoland, which he thinks there 

 can be no doubt is accomplished by first crossing the Atlantic 

 and afterwards the British Isles or France, he is ready to assert 

 in support of his favourite theory of an east to west flight, that 

 the example of Turdus Swainsoni, captured October 2nd, 1869, 

 "no doubt reached this island by an east to west route of 

 migration" (p. 116). The latter individual is thus required to 

 traverse the Pacific and the whole of the continents of Asia 

 and Europe. 



With reference to another species, i.e., Tringa maculata — to 

 which Herr Gatke draws attention, pointing to the fact that nine- 

 teen instances of its occurrence in England have been recorded, 

 it may be remarked that in the opinion of Mr. J. H. Gurney, 

 who has been at considerable pains in investigating each case, 

 very few are open to credence, mistaken identity being probable 

 in most instances. 



In objecting to the theory that birds may be blown across the 

 Atlantic by westerly gales, Herr Gatke alludes to the fact that 

 the Virginian Golden Plover is of the rarest occurrence in Europe, 

 contrary to what might be expected from the fact of its migrating 

 across the ocean in large numbers via the Bermudas to Brazil. 

 It is quite possible, however, that this Plover, from its close 

 resemblance to the Golden Plover, may be overlooked. Only an 

 ornithologist would detect the difference, and, moreover, he 



