Vol. XIII 



Allen, Giitke's- 'Heligoland.' I 7.Q 



beyond the power of man to solve. Hence we are led to a rather 

 close scrutiny of evidence and arguments so universally icono- 

 clastic. 



' Heligoland ' is indeed a remarkable book, and an important 

 contribution, from many points of view, to the literature of orni- 

 thology ; but it contains much that is set forth as fact which 

 on close examination proves to be mere conjecture. On many 

 points which Herr Giitke treats with great positiveness his knowl- 

 edge is obviously as limited as the little field which has been the 

 scene of his life-long labors. 



Herr Giitke's book consists of three parts, entitled respectively 

 'Migration of Birds' (pp. 3-148), 'Changes in the Color of the 

 Plumage of Birds without Moulting' (pp. 149-164), and 'Account 

 of the Birds observed in Heligoland' (pp. 165-588). Part I is 

 divided into eleven chapters or sections, relating to as many 

 phases of the general subject of bird migration. The first chapter 

 treats of the ' Course of Migration generally in Heligoland,' and 

 gives a history of bird movements at the island chronologically by 

 months from January to December. In style of treatment it is 

 not unlike accounts that have been given of many other localities 

 by various local observers, being a sort of calendar of the bird 

 year at Heligoland. Its special interest is therefore due to the 

 peculiar nature and geographic position of the island in relation 

 to the migration routes of birds, and the long period of observa- 

 tion on which the account is based. 



Chapter II (pp. 24-45) treats of the 'Direction of Flight.' 

 Here his observations and conclusions are quite at variance with 

 those of most observers at other points. He scouts the idea of 

 • Zugstrassen,' or restricted lines of migration, or concentrated 

 migration by favorite routes, and affirms that "the migratory 

 movement is performed by a broad front," which corresponds to 

 the breadth of the breeding area. He says, for example : " The 

 view, much discussed in recent years, that migrants follow the 

 direction of ocean coasts, the drainage area of rivers, or depres- 

 sions of valleys as fixed routes of migration, can hardly be main- 

 tained. Too many facts are directly at variance with this 

 assumption" (p. 24). In proof of his view he cites the east and 

 .west migration of many species which, breeding in northeastern 



