4-76 THE PHiLOSOPHy 



CHAPTER XX. 



Of the Aligrailcn of Ammcih» 



X HE Kon. Dallies Barrington, In his Ejja^ on the 

 Periodical Appearing ami Difappearing of certain Birds y at differ^ 

 ent times of the year'^y has, by many Ingenious arguments, as 

 well as curious fa^ls, rendered it extremely probable, that no 

 birds, however ftrong and fwift In their flight, can poflibly 

 fly over fuch large trails of the ocean as has been commonly 

 fuppcfed. He admits partial migrations or fittings, as he 

 calls them, though he does not attempt to afcertain the dif- 

 tances of thefe flittlngs. With regard to the fwallows, of 

 which there are feveral fpecies in Britain, fome natural ifts, 

 of whom the Hon. Daines Barrington is one, are inclined to 

 think that they do not leave this ifland at the end of autumn, 

 but that they lie in a torpid ftate till the beginning of fum- 

 mer in the banks of the rivers, the hollows of decayed trees, 

 the recefles of old buildings, the holes of fand-banks, and in 

 fimilar fltuations. That fwallows, in the winter months, 

 have fometimes, though very rarely, been found in a torpid 

 flate, is unqueftionably true. Neither is the inference, that, 

 if any of them can furvive the winter in that fl:ate, the 

 whole of them, may fubfift, during the cold feafon, in the 

 fame condition, in the fmallell degree unnatural. Still, how- 

 ever, the numbers of fwallows which appear in this ifland, 

 as well 4s in all parts of Europe, during the fummer months, 

 are fo very conflderable, that, if the great body of them did 

 not migrate to fome other cliniate, they fliould be much 

 more frequently found in a torpid ftate. On the contrary, 

 v«^hen a few of them are difcovered in that fl:ate, it is regarded 

 • Phil. Tranfadl, vol. 62, page 265, &c. 



