18 



migration conducted in a broad front, and travelling west, would, 

 on turning south at an identical longitude, naturally be converted 

 into a comparatively narrow flight, and bearing no relation what- 

 ever to the latitudinal area of the breeding ground. It seems 

 more probable that these migratory Crows would follow the 

 eastern shores of the Baltic in preference to making an attempt to 

 cross to the opposite coast in continuation of their westerly flight : 

 for, as has been pointed out before, if they still persisted in a 

 flight in the latter direction as far as shores of the Atlantic, they 

 would hardly be likely to touch at Heligoland at all. Birds are 

 very conservative in their habits, and there can be little doubt 

 that inheritance comes largely into play when the locality of their 

 winter home has to be determined. If we grant that the nature 

 of migration at its first inception is to-day best represented by 

 the intermittent movements of those species which may be said 

 to hang about the fringe of the severest cold, we can understand 

 that the habit of crossing wide seas, as is the practice of birds 

 at the present time, must have been a later development; not 

 from any lack of powers of flight, but more from a reluctance to 

 attempt a journey leading to some unseen and unknown goal : 

 indeed, the pioneers in a movement of this nature must, as far 

 as we can see, have first undertaken such a flight through an 

 accident or by force of circumstances, rat'her than design. We 

 cannot imagine birds to have been gifted with a sense which 

 enabled them to detect the presence of land in the far distance, 

 and beyond their range of vision at this early stage of the develop- 

 ment of the migratory habit. Thus the flights of Hooded Crows 

 are more likely at this early period to have followed the coast 

 line of such seas as they encountered, and have continued to do 

 so to the present day. According to Herr Gatke's view, how- 

 ever, it is not the sight of the sea which turns birds to the 

 south, though he does not tell us his reasons for coming to this 

 conclusion. In bringing forward evidence in favour of the far 

 eastern origin of these great flights of Hooded Crows, Herr Gatke 

 is apt to lay too great stress on the fact that their direct westerly 

 flight can be traced over a distance of six hundred miles, i.e., 

 from the shores of Schleswig Holstein to the interior of England ; 

 but it can readily be proved that only a small proportion, if any. 



