124 . THE BIRDS OF HELIGOLAND 



which these birds may have reached us from their distant homes. 

 That they should have crossed that vast waste of waters the 

 Atlantic was at first either disbelieved or only admitted with much 

 reserve, mainly because it was considered quite impossible for a 

 bird to sustain the uninterrupted flight of at least sixteen hundred 

 geographical miles involved in such a journey. 



Instead of at once entering into the consideration as to the 

 possibility of such a feat, it would perhaps be wiser to examine 

 which of the two routes leading from America to Europe seems the 

 more likely to be adopted by migrants that to the east over the 

 ocean, or, otherwise, the so-called overland route through Asia and 

 eastern Europe. For this purpose a comparison of the lists of rare 

 and exceptional occurrences in Germany, including Heligoland, with 

 that of the similar occurrences in England, at one glance decides 

 this question in a most convincing manner. Because, whereas 

 Germany can show an unexampled number of Asiatic species, with 

 only extremely isolated instances of American birds, England mar- 

 shals a perfect flood of American species, and individuals among 

 which only a few scattered visitors from Asia are found. These facts 

 speak clearly enough ; it is impossible that two hundred and fifty 

 birds should travel from America through Asia and the greater 

 part of the continent of Europe to England without more than ten 

 of their number being observed or killed in Germany ; on the other 

 hand, all the facts point to the conclusion that the birds reached 

 the coasts of England direct by way of the Atlantic Ocean. Nor 

 indeed could a large number of birds like that have travelled vid 

 Greenland, Iceland, the Fseroes and Shetland, as one might have felt 

 inclined to assume, without leaving behind them more extensive 

 traces than it has been possible, in spite of all efforts, to demonstrate. 

 It seems the more surprising that, instead of investigating the 

 possibility of such a direct transmarine flight, people have so long 

 objected to accept this view, since proofs of its actual occurrence 

 have come to light frequently enough. Thus it has been long 

 known as a common occurrence, that ships half way between 

 Europe and America have fallen in with birds travelling, either 

 singly or in flocks, in an easterly direction, migrants of this 

 kind having not rarely attempted to alight upon the rigging, and 

 some having also been caught there. A case of this kind is 

 mentioned by Professor Alfred Newton (Yarrell, British Birds, 

 fourth edition, ii. p. 220), according to which Dr. Dewar observed 

 on his passage from America, about six hundred geographical miles 

 east of Newfoundland, flocks of the American White-winged Cross- 

 bill crossing the Atlantic before a stiff westerly breeze. Many of 

 the flocks alighted on the rigging of the ship, and of these twelve 

 examples were captured. One or two of the latter escaped as the 



