500 THE BIRDS OF HELIGOLAND 



in Australia and New Zealand. Therefore, those of the birds which 

 have migrated from a latitude of 80' N. to one of 45° S. will have 

 accomplished a distance of nearly eight thousand miles, their journey 

 having led them from the ice-bound regions of the north to lands 

 glowing beneath the rays of the equatorial sun, and thence once 

 more to temperate climes. One may feel inclined to ask why the 

 birds did not terminate their migration on reaching in the northern 

 hemisphere a climate similarly conditioned to that of their final 

 winter home south of the equator. While, however, the immense 

 and apparently unnecessary latitudinal extent of this migratory 

 flight presents us with an insoluble problem, its equally wide 

 longitudinal range offers a weighty support for assuming, as we 

 have intimated above, that there exists an extensive insular or 

 continental area between the points reached by the Jeanveite in 

 1881 and the Pole. For it is out of the question that Grinncll Land 

 and the neighbouring regions in the western hemisphere could be 

 the breeding area of those birds which travel down to Australia 

 and New Zealand in the eastern half of the globe. Or whither, 

 we may ask, were those individuals wending their course which 

 were met with during the spring migration by Middeiidorti' at the 

 Sea of Ochotsk, by Dr. Bunge in New Siberia (Dr. Bunge, Great 

 Lialxoff Island; Ibis, 1888, jj. 344), and by the Jeannefte during its 

 disastrous expedition in search of the Pole ? Only one answer is 

 possible, viz. — northwards, to a district of such extent and character 

 as to aft'ord suitable nesting places to the present species, as it does 

 to others like Tringa suharqiiata and T. arenaria, Anser torquattis, 

 Larus rossei, and numerous other species in the Arctic. Where 

 else could wc find such a region unless it bo between the Jean- 

 nettc Islands and the Pole ? Unfortunately, insurmountable 

 masses of ice still prevent us, with the means at present at our 

 command, to reach this ornithological trcasui'C-house ; but should 

 it ever be possible to construct balloons the motion of which could 

 be under the complete control of the aeronaut, and the Jeannette 

 Islands were made the starting-point of such an expedition, there 

 is little doubt that this question could be solved with compara- 

 tively little difficulty. The observations of Dr. Bunge on Liakhov 

 Island furnish, besides other interesting material, imequivocal proof 

 of the determining influence of meteorological conditions, at the 

 time being, on the occurrence of birds ; because in the case of most 

 of the .species ob.sorved in that locality individuals observed nu'grat- 

 ing were similar — in greater or less numbers — on days with the 

 same kind of weather, i.e. when the birds were subjected to similar 

 influences. Thus, on tht^ Nth of June, Trinija rainitit.v and 

 T. suharquata were observed in small flights, and on the 14th, more 



