APPENDIX. 



No. VI. 



Of the MIGRATION of BRITISH 

 BIRDS. 



Quam mult a glomerantur aves ! ubi frlgidus annus 

 Trans pontum fugat> et terris immittit apricis. 



Virgil. 



THE migration of birds, is a fubject of fo 

 curious a nature, that every one who at- 

 tempts to write the natural hiftory of animals, ought 

 to look upon it as an eiTential part of his inquiries, 

 and at the fame time mould endeavour to affig-ri the 

 caufe why fome birds prefer certain places for their 

 fummer, others for their winter refidence. 



To be qualified for this tafk, it is necelTary 

 that the inquirer mould confine himfelf to one cer- 

 tain tract the whole year; "he mould be diligent 

 in obferving the arrival, and the difappearance 

 of birds; he lhould commit every obiervation to 

 paper, and compare them with the remarks of 

 correfpondents, on the fame fubject, that lie on eve- 

 ry fide of him. He mould attend likewife to the 

 weather; and to the plenty or failure of fruits and 

 A a a 2 berries ; 



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