41 



eastern coast of Great Britain — including the Orkney and Shet- 

 land Islands — Norway up to a latitude of TO"" N. in Finmark, 

 the same results as to the direction of the migratory flight have 

 been obtained." 



Why certain species should follow such a course, and the 

 remainder should fly from north to south, he offers not a word in 

 explanation, and he quite ignores the results of inquiries con- 

 ducted by ornithologists like the late Dr. Severzoff, as regards 

 Central Asia ; and Dr. Menzl^ier as regards Eastern Europe ; or, 

 again, by Von Middendorff, who, after selecting seven typical 

 species, found that in the middle of Siberia the general direction 

 of the usual migrants is almost due north, in the east of Siberia 

 from south-east to north-west, and in European Eussia from 

 south-west to north-east. Prof. Palmen's conclusions are similar. 

 Whether we accept the theories of the latter as to the manner 

 in which birds are guided, or not, is of little importance at the 

 present juncture, and does not aliect the accuracy of his state- 

 ments on the direction of the migratory flight. 



It is no doubt true, as pointed out by Dr. Menzbier, that there 

 are no such things as fly-lines. Probably every species goes its 

 own way, and what is called a migration route is only the co- 

 incidence of the way taken by many (Newton, "Dictionary of 

 Birds "). How Herr Gatke, however, can formulate a theory of a 

 migration carried out in a broad front, corresponding to the lati- 

 tudinal area of the breeding-ground, and rigidly conducted in an 

 east-to-west direction, in the face of the heterogeneous assem- 

 blage of individuals and species which pass with such regularity 

 and in such wonderful proportions at his little island, is im- 

 possible to imagine. With regard to the confirmatory evidence 

 of a general migration in an east-to-west direction, afforded by 

 the capture of a few Siberian species during a period of more 

 than fifty years, as well might it be argued, from the occurrence 

 of over 260 American birds in Great Britain in the same lapse 

 of time, that the general tendency of migration in the latter 

 continent is in the reverse direction. 



In objecting to the theory that birds follow coast Lines as 

 guides during their migration, Herr Gatke, referring to Eichard's 

 Pipit, and others, inquires — " Are we, therefore, to assume that 



