MIGRATION OF BIRDS. 47 



and Newton, that the oceanic, wandering of land-birds must be 

 attributed in most, or nearly all, cases to accidental circumstances — 

 namely, storms, or the prevalence of certain winds — wliich may 

 have wafted the birds beyond their control ofl to sea. Winds 

 from the west, as has been shown by Professor Baird, are preva- 

 lent between latitudes 32° and 58° N., and, hence, would- be liable 

 to catch such birds as may be passing southward during their au- 

 tumnal migration, especially there where their flight would be 

 at some distance ofE from the shore, or across broad arms or in- 

 lets of the sea. The dispersal would naturally be facilitated by 

 the interaction of a heavy storm, and it is a most noteworthy 

 confirmatory fact that the appearance of American birds on the 

 European coast is either presaged or accompanied by heavy westerly 

 winds blowing in that quarter. North of the fifty-eighth parallel 

 of latitude the polar winds trend westward, and with them we 

 have the accompanying transferrenoe of European birds, by way of 

 Iceland and Greenland, to the American continent. That storms 

 or heavy winds do influence the flight of birds in the manner here 

 described, is indisputably proved by the facts that present them- 

 selves in connection with the occurrence of marine birds over con- 

 tinental areas at some distance from the shore-line. The stormy 

 petrel, during and after the prevalence of a northeast storm, has 

 been seen in considerable numbers in the Eastern United States 

 beyond the Alleghany Mountains; the Thalassidroma Leachii has 

 been abundantly killed at or about the city of Washington ; and 

 Professor Baird instances the case of a Pomarine jager fCataractes 

 Pomarinus), which was killed on the Susquehanna, at Harrisburg, 

 in 1842.''° The golden plovers, in their southerly flight, start di- 

 rect from Nova Scotia or Newfoundland for the West Indies, 

 whence they continue their jpurney along the South American 

 coast to Patagonia. In this journey but compo,ratively few in- 

 dividuals touch or rest along the Atlantic States, yet it is known 

 that during heavy northeastern winds, in the month of August, 

 great numbers of the birds may be confidently expected along the 

 New England coast. And it not infrequently happens that un- 

 der similar conditions immense numbers of these and allied birds 

 are driven to very considerable distances in the interior of the 

 continents. In a like manner, during the prevalence of heavy 

 storms, European birds are cast upon the Azores, situated about 



