THE ORNITHOLOGIST IN HELIGOLAND. 365 



The statistics furnished by Herr Gatke under these several 

 headings are some of them very curious, and to those who are 

 not professed ornithologists will probably be new. 



" A large portion of the migrants," says Herr Gatke, " travel 

 within an east to west, another within a north to south, line of 

 flight. Species which fail to find satisfactory winter quarters in 

 the western countries of Europe, on arriving in these districts 

 deviate from their westerly course, and pursue their journey in a 

 southward direction. 



*' Those, on the other hand, whose autumn migration takes 

 place in a southerly direction, persevere in their course from 

 their breeding-station to the end of their journey, though some 

 may make a more or less considerable deviation to the east. 



" The predominant mode in which the migratory movement is 

 performed is in a broad front or migration column, which in the 

 case of species migrating to the west corresponds to the latitudinal 

 range of their breeding area, and in those migrating southwards 

 to the longitudinal extent of their nesting stations." 



The view much discussed in recent years, that migratory 

 birds follow the coast lines, the drainage area of rivers, or 

 depressions of valleys as fixed routes of migration, can, in the 

 opinion of Herr Gatke, hardly be maintained. Too many facts, 

 to some of which he refers, are at variance, he says, with this 

 assumption. Direct observations in Heligoland have established 

 the fact that in autumn the migration proceeds from east to west, 

 and in spring in the opposite direction. Not all birds, however, 

 reach their winter quarters by proceeding in a westward direction, 

 some being sooner or later obliged to turn southwards in order to 

 reach their destination. 



The following curious observation shows the close attention 

 which Herr Gatke has paid to the subject on which he writes: — 



" During the autumn migration it frequently happens that 

 when out at sea birds are carried into air currents stronger than 

 is suitable to their line of flight, a violent S.E. wind being 

 especially unfavourable. To escape this wind blowing obliquely 

 through their plumage from behind, they turn their body south* 

 wards and appear to be flying in that direction. This, however, 

 is not the case. They do not make the least forward progress to 

 the south, but their flight is continued in as exact a westerly 

 course, and with the same speed, as though the birds were moving 



