30 



i6oo miles between Egj'pt, its winter home, and Heligo- 

 land, during the course of a spring night. Mr. J. M. 

 Jones, in The Naturalist hi Benmida, tells us how the 

 Virginian Plover travels from Hudson Bay Territory 

 and Labrador to the south of Brazil, over 3000 miles, 

 without resting. Vast flocks of these birds have been 

 watched for days and nights together, flying over the 

 Atlantic, 600 miles east of Bermuda, the journey of 

 each individual probably occupying less than fifteen 

 hours. 



What guides the birds during their migrations is 

 still a myster5^ "Any one," says Gatke, "who, on 

 dark starless autumn nights, has heard the babel of 

 voices of the hundreds of thousands, and even millions, 

 of birds travelling past him overhead, in one fixed 

 direction, . . . without the help of any guiding mark 

 discernible by human eye, cannot fail to be led .... 

 to speculate as to what kind of capacities the unfailing 

 performance of such an act is due." Such speculations 

 there are, but few are in the least degree satisfactory. 



Dr. von Middendorfif, however, in his Siberische 

 y?m<? (Siberian Voyage), gives a valuable hint in this 

 connection. He remarks the wonderful "sense of 

 direction (Jiu/itsmji) possessed by the Samoyedes who 

 travel on the vast tundras of Northern Asia, a " sense" 

 which is known to be possessed by other savage races ; 

 and he argues that it is this faculty enormously ex- 

 aggerated which enables migrating flocks to judge the 

 direction of their flight. 



On the theories which have been advanced on the 

 subject of the primary origin of migration it is not 

 necessary to dwell here. Those dealing with the more 

 immediate causes can scarcely be regarded as satis- 

 factory. That change of temperature and failure of 

 food supply do, to some extent, impel the species 

 which breed in temperate latitudes to shift their 



